Liquid crystal display device

ABSTRACT

A liquid crystal display device is provided. The liquid crystal display device including a first substrate; a second substrate; a first electrode provided on a first surface of the first substrate, the first surface facing the second substrate, the first electrode including a plurality of convex and concave portions; a second electrode provided on a second surface of the second substrate; and a liquid crystal layer provided between the first substrate and the second substrate.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.14/395,924 filed Oct. 21, 2014, which is a national stage ofInternational Application No. PCT/JP2013/002498 filed Apr. 11, 2013,which claims priority to Japanese Application No. 2012-102884 filed Apr.27, 2012, the disclosures of which are incorporated herein by reference.

BACKGROUND

The present disclosure relates to a liquid crystal display deviceprovided with a liquid crystal display element in which a liquid crystallayer is sealed between a pair of substrates, each of which has anoriented film on a facing surface.

In recent years, liquid crystal displays (LCDs) have been widely used asdisplay monitors of a liquid crystal television receiver, a note-typepersonal computer, a car navigation apparatus, and the like. Such liquidcrystal displays are classified into various display modes (schemes)depending on molecular alignment (orientation) of liquid crystalmolecules included in the liquid crystal layer interposed betweensubstrates. As a display mode, a TN (Twisted Nematic) mode in which theliquid crystal molecules are oriented in a twisted manner in a state inwhich no voltage is applied has been well known, for example. In the TNmode, the liquid crystal molecules have positive dielectric constantanisotropy, namely, a characteristic that a dielectric constant of theliquid crystal molecules in a long axial direction is greater than thatin a short axial direction. For this reason, the liquid crystalmolecules have a structure in which the liquid crystal molecules arealigned in a perpendicular direction to a substrate surface while anorientation direction of the liquid crystal molecules is subsequentlyrotated in a plane which is parallel to the substrate surface.

On the other hand, a VA (Vertical Alignment) mode in which the liquidcrystal molecules are oriented so as to be perpendicular to thesubstrate surface in a state in which no voltage is applied has drawnmore attention. In the VA mode, the liquid crystal molecules havenegative dielectric constant anisotropy, namely, a characteristic that adielectric constant of the liquid crystal molecules in the long axialdirection is smaller than that in the short axial direction, and it ispossible to realize a wider viewing angle than that in the TN mode.

A liquid crystal display in the VA mode as described above has aconfiguration in which light is transmitted by causing the liquidcrystal molecules oriented in the perpendicular direction to thesubstrate to respond to voltage application so as to lie down in aparallel direction to the substrate due to a negative dielectricconstant anisotropy. However, since the direction in which the liquidcrystal molecules oriented in the perpendicular direction to thesubstrate lie down is arbitrary, the orientation of the liquid crystalmolecules becomes disorganized due to voltage application, which causesdeterioration of a responsive characteristic to voltage.

Thus various methods for regulating the orientation of the liquidcrystal molecules during voltage application have been proposedhitherto. For example, an MVA (Multi-domain Vertical Alignment) scheme,a PVA (Patterned Vertical Alignment) scheme, or a method using aphoto-alignment film (see PTL 1, for example) have been proposed.According to the PVA scheme, a wide viewing angle is realized while theorientation is controlled by using a slit or a rib (protrusion). Inaddition to this, a structure (also referred to as a fine slitstructure) in which a plurality of minute slits are provided in anelectrode (specifically, a pixel electrode) formed in one substrate andan electrode formed (specifically, a facing electrode) in the othersubstrate is formed as a so-called solid electrode with no slit has beenrecently proposed (see PTL 2, for example). However, the fine slitstructure has a problem that transmittance is lowered since a part towhich an electric field is not applied is present in a slit including aminute line and a space and further the orientation state of the liquidcrystal molecules takes a twisted structure in the vicinity of an edgeof the line during voltage application.

A technique to solve such a problem, namely a technique of formingconcave and convex portions instead of the plurality of minute slits hasbeen disclosed in PTL 3.

CITATION LIST Patent Literature

[PTL 1] Japanese Unexamined Patent Application Publication No. 5-232473

[PTL 2] Japanese Unexamined Patent Application Publication No.2002-357830

[PTL 3] Japanese Unexamined Patent Application Publication No.2011-232736

SUMMARY Technical Problem

Although it is possible to effectively suppress occurrence of theaforementioned problem in the fine slit structure by the techniquedisclosed in PTL 3, there is a requirement that the occurrence of a darkline is further suppressed, namely a strong requirement to realizefurther uniform high transmittance. In addition, there is also a strongrequirement for a more satisfactory voltage responsive property.

Accordingly, it is desired to provide a liquid crystal display devicecapable of achieving a more satisfactory voltage responsive property andrealizing further uniform high transmittance.

Solution to Problem

There is provided a liquid crystal display device according to Modes 1to 4 of the present disclosure including: a plurality of aligned pixels,each of which includes a first substrate and a second substrate, a firstelectrode which is formed on a facing surface of the first substratefacing the second substrate, a first oriented film which covers thefirst electrode and the facing surface of the first substrate, a secondelectrode which is formed on a facing surface of the second substratefacing the first substrate, a second oriented film which covers thesecond electrode and the facing surface of the second substrate, and aliquid crystal layer which is provided between the first oriented filmand the second oriented film and includes liquid crystal molecules,wherein a pre-tilt is applied to the liquid crystal molecules by atleast the first oriented film.

In the liquid crystal display device according to Mode 1 of the presentdisclosure, a plurality of concave and convex portions are formed on aflattened layer on which the first electrode is formed, and a pluralityof stepped portions are formed at the convex portions included on thefirst electrode.

In the liquid crystal display device according to Mode 2 of the presentdisclosure, a plurality of concave and convex portions are formed on aflattened layer on which the first electrode is formed, a convexstructure is formed from a part of the first substrate positionedbetween pixels to a part of the first substrate corresponding to a pixelcircumferential portion, and a circumferential portion of the concaveand convex portions are formed on the convex structure.

In the liquid crystal display device according to Mode 3 of the presentdisclosure, a plurality of concave and convex portions are formed on aflattened layer on which the first electrode is formed, the concave andconvex portions are configured by convex stem portions which passthrough a pixel center portion and extend in a cross shape and aplurality of branched convex portions which extend from the convex stemportions toward a pixel circumferential portion, and an orientationregulating portion is formed at a part of the second electrodecorresponding to the convex stem portions.

In the liquid crystal display device according to Mode 4 of the presentdisclosure, a plurality of concave and convex portions are formed on aflattened layer on which the first electrode is formed, the concave andconvex portions are configured by a convex stem portion which is formedin a frame shape at a pixel circumferential portion and a plurality ofbranched convex portions which extend from the convex stem portiontoward the inside of the pixel, and a slit portion or a protrudingportion which passes through a pixel center portion and is in parallelwith the pixel circumferential portion is formed on the first electrode.

According to one embodiment, the present disclosure provides a liquidcrystal display device comprising: a first substrate; a secondsubstrate; a first electrode formed on a first surface of the firstsubstrate, the first surface facing the second substrate, the firstelectrode including a plurality of convex and concave portions; a firstoriented film formed on the first surface of the first substrate; asecond electrode formed on a second surface of the second substrate, thesecond surface facing the first substrate; and a liquid crystal layerprovided between the first substrate and the second substrate. At leastone of the convex portions includes a plurality of stepped portions.

According to an embodiment, the present disclosure provides a liquidcrystal display device comprising: a first substrate; a secondsubstrate; a first electrode formed on a first surface of the firstsubstrate, the first surface facing the second substrate, the firstelectrode including a plurality of convex and concave portions; a firstoriented film formed on the first surface of the first substrate; asecond electrode formed on a second surface of the second substrate, thesecond surface facing the first substrate; and a liquid crystal layerprovided between the first substrate and the second substrate. A convexstructure is formed from a part of the first substrate positionedbetween pixels to a part of the first substrate corresponding to a pixelcircumferential portion, and a circumferential portion of the concaveand convex portions is formed on the convex structure.

According to an embodiment, the present disclosure provides a liquidcrystal display device comprising: a first substrate; a secondsubstrate; a first electrode formed on a first surface of the firstsubstrate, the first surface facing the second substrate, the firstelectrode including a plurality of convex and concave portions; a firstoriented film formed on the first surface of the first substrate; asecond electrode formed on a second surface of the second substrate, thesecond surface facing the first substrate; and a liquid crystal layerprovided between the first substrate and the second substrate. Theconvex and concave portions are configured by convex stem portions thatpass through a pixel center portion and extend in a cross shape and aplurality of branched convex portions that extend from the convex stemportions toward a pixel circumferential portion. An orientationregulating portion is formed at a part of the second electrodecorresponding to the convex stem portions.

According to an embodiment, the present disclosure provides a liquidcrystal display device comprising: a first substrate; a secondsubstrate; a first electrode formed on a first surface of the firstsubstrate, the first surface facing the second substrate, the firstelectrode including a plurality of convex and concave portions; a firstoriented film formed on the first surface of the first substrate; asecond electrode formed on a second surface of the second substrate, thesecond surface facing the first substrate; and a liquid crystal layerprovided between the first substrate and the second substrate. Theconvex and concave portions are configured by a convex stem portion thatis formed in a frame shape at a pixel circumferential portion and aplurality of branched convex portions that extend from the convex stemportion toward the inside of a pixel. At least one of a slit portion anda protruding portion is formed on the first electrode, and the at leastone of a slit portion and a protruding portion passes through a pixelcenter portion and is in parallel with the pixel circumferentialportion.

According to an embodiment, the present disclosure provides a method ofmanufacturing a liquid crystal display device comprising: forming afirst oriented film on a first electrode, the first electrode formed ona first surface of a first substrate; forming a second oriented film ona second electrode, the second electrode formed on a second surface of asecond substrate, the second oriented film facing the first orientedfilm; sealing a liquid crystal layer between the first and secondoriented films; applying a voltage between the first and secondelectrodes; and irradiating the first and second oriented films with anultraviolet ray while applying the voltage.

Advantageous Effects of Present Disclosure

Since a plurality of stepped portions (height differences) are formed inthe convex stem portions in the liquid crystal display device accordingto Mode 1 of the present disclosure, the strength of an electric fieldvaries in the convex stem portions, or a horizontal electric field isgenerated. As a result, it is possible to enhance the orientationregulating force for the liquid crystal molecules in the convex stemportions and reliably define a tilt state of the liquid crystalmolecules in the convex stem portions. For this reason, it is possibleto reliably suppress an occurrence of a problem that a dark line isgenerated at a part of an image corresponding to the convex stemportions during display of the image. That is, it is possible to providea liquid crystal display device capable of realizing further uniformhigh transmittance while maintaining a satisfactory voltage responsivecharacteristic, reduce the cost of a light source configuring a backlight and power consumption, and also enhance reliability of the TFT.

In addition, since the circumferential portion of the concave and convexportions are formed on the convex structure in the liquid crystaldisplay device according to Mode 2 of the present disclosure, a strongerelectric field is generated in the circumference of the concave andconvex portions as compared with a case in which the circumferentialportion of the concave and convex portions are flat. As a result, it ispossible to enhance the orientation regulating force for the liquidcrystal molecules in the circumferential portion of the concave andconvex portions and reliably define a tilt state of the liquid crystalmolecules in the circumferential portion of the concave and convexportions. For this reason, it is possible to maintain a satisfactoryvoltage responsive characteristic.

Moreover, since the orientation regulating portion is formed at a partof the second electrode corresponding to the convex stem portions in theliquid crystal display device according to Mode 3 of the presentdisclosure, an electric field generated by the second electrode isdeformed in the vicinity of the orientation regulating portion, orotherwise, directions in which the liquid crystal molecules lie down inthe vicinity of the orientation regulating portion are defined. As aresult, it is possible to enhance the orientation regulating force forthe liquid crystal molecules in the vicinity of the orientationregulating portion and reliably define a tilt state of the liquidcrystal molecules in the vicinity of the orientation regulating portion.For this reason, it is possible to reliably suppress occurrence of aproblem that a dark line is generated at a part of an imagecorresponding to the convex stem portions during display of the image.That is, it is possible to provide a liquid crystal display devicecapable of realizing further uniform high transmittance whilemaintaining a satisfactory voltage responsive characteristic, reduce thecost of a light source configuring a back light and power consumption,and also enhance reliability of the TFT.

Since the slit portion or the protruding portion which passes throughthe pixel center portion and is in parallel with the pixelcircumferential portion is formed on the first electrode in the liquidcrystal display device according to Mode 4 of the present disclosure, anelectric field generated by the first electrode is deformed, ordirections in which the liquid crystal molecules lie down in thevicinity of the projecting portion and the orientation regulatingportion are defined as compared with a case in which a flat concaveportion with no slit portion and protruding portion is formed on thefirst electrode. As a result, it is possible to enhance the orientationregulating force for the liquid crystal molecules in the vicinity of theslot portion or the protruding portion and reliably define a tilt stateof the liquid crystal molecules in the vicinity of the slit portion orthe protruding portion. For this reason, it is possible to reliablysuppress a problem that a dark line is generated at a part of an imagecorresponding to the convex stem portion during display of the image.That is, it is possible to provide a liquid crystal display devicecapable of realizing further uniform high transmittance whilemaintaining a satisfactory voltage responsive characteristic, reduce thecost of a light source configuring a back light and a power consumption,and also enhance reliability of the TFT.

Additional features and advantages are described herein, and will beapparent from the following Detailed Description and the figures.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a partial end surface view schematically showing a liquidcrystal display device according to Example 1.

FIG. 2 is a planar view schematically showing a first electrodecorresponding to a pixel, which configures the liquid crystal displaydevice according to Example 1.

FIG. 3A is a partial cross-sectional view schematically showing a firstelectrode and the like taken along the arrow IIIA-IIIA in FIG. 2 in theliquid crystal display device according to Example 1.

FIG. 3B is a partial cross-sectional view schematically showing a firstelectrode and the like taken along the arrow IIIB-IIIB in FIG. 2 in theliquid crystal display device according to Example 1.

FIG. 3C is a partial cross-sectional view schematically showing a firstelectrode and the like taken along the arrow IIIC-IIIC in FIG. 2 in theliquid crystal display device according to Example 1.

FIG. 3D is a partial cross-sectional view schematically showing a partof FIG. 3C in an enlarged manner.

FIG. 4A is a conceptual diagram showing a behavior of liquid crystalmolecules in a liquid crystal display device in the related art.

FIG. 4B is a conceptual diagram showing a behavior of liquid crystalmolecules in the liquid crystal display device according to Example 1.

FIG. 5 is a planar view schematically showing a first electrodecorresponding to a pixel, which configures a liquid crystal displaydevice according to Example 2.

FIG. 6 is a planar view schematically showing a first electrodecorresponding to a pixel, which configures a liquid crystal displaydevice according to Example 3.

FIG. 7A is a partial cross-sectional view schematically showing thefirst electrode and the like taken along the arrow VIIA-VIIA in FIG. 5in the liquid crystal display device according to Example 2.

FIG. 7B is a partial cross-sectional view schematically showing thefirst electrode and the like taken along the arrow VIIB-VIIB in FIG. 5in the liquid crystal display device according to Example 2.

FIG. 7C is a partial end surface view schematically showing the firstelectrode and the like taken along the arrow VIIC-VIIC in FIG. 6 in theliquid crystal display device according to Example 3.

FIG. 7D is a partial end surface view schematically showing a par ofFIG. 7C in an enlarged manner.

FIG. 8 is a planar view schematically showing a modified example of thefirst electrode corresponding to a pixel, which configures the liquidcrystal display device according to Example 3.

FIG. 9 is a perspective view schematically showing another modifiedexample of the first electrode corresponding to a pixel, whichconfigures the liquid crystal display device according to Example 3.

FIG. 10 is a planar view schematically showing a first electrodecorresponding to a pixel, which configures a liquid crystal displaydevice according to Example 4.

FIG. 11 is a perspective view schematically showing the first electrodecorresponding to a pixel, which configures the liquid crystal displaydevice according to Example 4 shown in FIG. 10.

FIG. 12 is a planar view schematically showing a first electrodecorresponding to a pixel, which configures a liquid crystal displaydevice according to Example 5.

FIG. 13A is a partial end surface view schematically showing a firstelectrode and the like taken along the arrow XIIIA-XIIIA in FIG. 10 inthe liquid crystal display device according to Example 4.

FIG. 13B is a partial end surface view schematically showing the firstelectrode and the like taken along the arrow XIIIB-XIIIB in FIG. 10 inthe liquid crystal display device according to Example 4.

FIG. 13C is a partial end surface view schematically showing a part ofFIG. 13B in an enlarged manner.

FIG. 13D is a partial end surface view schematically showing a part of afirst electrode taken along the arrow XIIID-XIIID in FIG. 12 in theliquid crystal display device according to Example 5 in an enlargedmanner.

FIG. 14 is a planar view schematically showing a first electrodecorresponding to a pixel configuring a liquid crystal display deviceaccording to Example 6.

FIG. 15 is a perspective view schematically showing a modified exampleof a first electrode corresponding to a pixel configuring the liquidcrystal display device according to Example 6.

FIG. 16 is a planar view schematically showing a first electrodecorresponding to a pixel configuring a liquid crystal display deviceaccording to Example 7.

FIG. 17 is a planar view schematically showing a modified example of afirst electrode corresponding to a pixel configuring the liquid crystaldisplay device according to Example 7.

FIG. 18 is a partial cross-sectional view schematically showing thefirst electrode and the like taken along the arrow XVIIIA-XVIIIB in FIG.16 in the liquid crystal display device according to Example 7.

FIG. 19 is a partial end surface view schematically showing a liquidcrystal display device according to Example 8.

FIG. 20 is a partial end surface view schematically showing a modifiedexample of the liquid crystal display device according to Example 8.

FIG. 21 is a planar view schematically showing a first electrodecorresponding to a pixel configuring a liquid crystal display deviceaccording to Example 9.

FIG. 22 is a planar view schematically showing a modified example of afirst electrode corresponding to a pixel configuring the liquid crystaldisplay device according to Example 9.

FIG. 23 is a planar view schematically showing another modified exampleof a first electrode corresponding to a pixel configuring the liquidcrystal display device according to Example 9.

FIG. 24 is a planar view schematically showing a still another modifiedexample of a first electrode corresponding to a pixel configuring theliquid crystal display device according to Example 9.

FIG. 25A is a partial end surface view schematically showing the firstelectrode and the like taken along the arrow IIXVA-XXVA in FIG. 21 inthe liquid crystal display device according to Example 9.

FIG. 25B is a partial end surface view schematically showing the firstelectrode and the like taken along the arrow IIXVB-IIXVB in FIG. 21 inthe liquid crystal display device according to Example 9.

FIG. 25C is a partial end surface view schematically showing the firstelectrode and the like taken along the arrow IIXVC-IIXVC in FIG. 23 inthe liquid crystal display device according to Example 9.

FIG. 25D is a partial end surface view schematically showing the firstelectrode and the like taken along the arrow IIXVD-IIXVD in FIG. 23 inthe liquid crystal display device according to Example 9.

FIG. 26A is a diagram schematically illustrating a pre-tilt of liquidcrystal molecules.

FIG. 26B is a conceptual diagram showing a behavior of the liquidcrystal molecules in the liquid crystal display device according toExample 8.

FIG. 26C is a conceptual diagram showing a behavior of the liquidcrystal molecules in the liquid crystal display device according toExample 8.

FIG. 27 is a circuit configuration diagram of the liquid crystal displaydevice shown in FIG. 1.

FIG. 28A is a partial end surface view schematically showing a firstsubstrate before concave and convex portions are formed on the flattenedlayer, in which a TFT and the like are formed.

FIG. 28B is a partial end surface view schematically showing the firstsubstrate before the concave and convex portions are formed on theflattened layer, in which the TFT and the like are formed.

FIG. 29A is an image showing a transmittance simulation result inExample 1-A.

FIG. 29B is an image showing a transmittance simulation result inExample 1-B.

FIG. 29C is an image showing a transmittance simulation result inExample 1-C.

FIG. 30A is an image showing a transmittance simulation result inExample 1-D.

FIG. 30B is an image showing a transmittance simulation result inExample 8.

FIG. 30C is an image showing a transmittance simulation result in aComparative Example.

DETAILED DESCRIPTION

Although a description will be given of a present disclosure based onexamples with reference to the drawings, the present disclosure is notlimited to the examples, and various numerical values and materials inthe examples are described only for an illustrative purpose. Inaddition, a description will be given in the following order.

1. Overall Description Relating to Liquid Crystal Display DeviceAccording to the First to Fourth Modes of the Present Disclosure

2. Example 1 (Liquid Crystal Display Device According to Mode 1-A of thePresent Disclosure)

3. Example 2 (Modification of Example 1)

4. Example 3 (Another Modification of Example 1)

5. Example 4 (Liquid Crystal Display Device According to Mode 1-B of thePresent Disclosure)

6. Example 5 (Modification of Example 4)

7. Example 6 (Another Modification of Example 4)

8. Example 7 (Liquid Crystal Display Device According to Mode 2 of thePresent Disclosure Including Examples 1 to 6)

9. Example 8 (Liquid Crystal Display Device According to Mode 3 of thePresent Disclosure Including Liquid Crystal Display Devices According toMode 1-A and Mode 2-A of the Present Disclosure)

10. Example 9 (Liquid Crystal Display Device According to Mode 4 of thePresent Disclosure Including Liquid Crystal Display Devices According toMode 1-B and 2-B of the Present Disclosure) and Other Examples

1. Overall Description Relating to Liquid Crystal Display DeviceAccording to First to Fourth Modes of the Present Disclosure

In a liquid crystal display device according to Mode 1 of the presentdisclosure, it is possible to employ a configuration in which concaveand convex portions includes convex stem portions which pass through apixel center portion and extend in a cross shape and a plurality ofbranched convex portions which extend from the convex stem portion to apixel circumferential portion. In addition, such a mode will be referredto as a “liquid crystal display device according to Mode 1-A of thepresent disclosure” for convenience. Here, when an (X, Y) coordinatesystem in which the convex stem portions extending in the cross shaperespectively correspond to an X axis and a Y axis is assumed in theliquid crystal display device according to Mode 1-A of the presentdisclosure, it is possible to employ a configuration in which theplurality of branched convex portions occupying a first quadrant extendin parallel with a direction in which a value of a Y coordinateincreases when a value of an X coordinate increases, the plurality ofbranched convex portions occupying a second quadrant extend in parallelwith a direction in which a value of a Y coordinate increases when avalue of an X coordinate decreases, the plurality of branched convexportions occupying a third quadrant extend in parallel with a directionin which a value of a Y coordinate decreases when a value of an Xcoordinate decreases, and the plurality of branched convex portionsoccupying a fourth quadrant extend in parallel with a direction in whicha value of a Y coordinate decreases when a value of an X coordinateincreases.

In relation to a cross-sectional shape of the convex stem portion whenthe convex stem portion is cut by a virtual vertical plane which isperpendicular to an extending direction of the convex stem portion inthe liquid crystal device according to Mode 1-A of the presentdisclosure including the above preferred form, it is possible to employa configuration in which the convex stem portion has a cross-sectionalshape in which a stepped portion declines from a center of thecross-sectional shape of the convex stem portion toward an edge of thecross-sectional shape of the convex stem portion. In relation to across-sectional shape of the convex stem portion when the convex stemportion is cut by a virtual vertical plane which is parallel with theextending direction of the convex stem portion in the liquid crystaldisplay device according to Mode 1-A of the present disclosure includingthe aforementioned various preferred configurations, it is possible toemploy a configuration with a cross-sectional shape in which a steppedportion declines from the center portion of the cross-sectional shape ofthe convex stem portion toward the end of the cross-sectional shape ofthe convex stem portion.

Moreover, in relation to a cross-sectional shape of the branched convexportion when the branched convex portion is cut by a virtual verticalplane which is orthogonal to an extending direction of the branchedconvex portion in the liquid crystal display device according to Mode1-A of the present disclosure including the aforementioned variouspreferred configurations, it is possible to employ a configuration witha cross-sectional shape in which a stepped portion declines from acenter of the cross-sectional shape of the branched convex portiontoward an edge of the cross-sectional shape of the branched convexportion. In addition, a cross-sectional shape of the branched concaveportion when the branched convex portion is cut by a virtual verticalplane which is parallel with the extending direction of the branchedconvex portion in the liquid crystal display device according to Mode1-A of the present disclosure including the aforementioned variouspreferred configurations, it is possible to employ a configuration witha cross-sectional shape in which a stepped portion declines from thecross-sectional shape of the branched convex portion on a side of theconvex stem portion toward an end of the cross-sectional shape of thebranched convex portion.

Furthermore, it is possible to employ a configuration in which anorientation regulating portion is formed at a part of a second electrodecorresponding to the convex stem portions in the liquid crystal displaydevice according to Mode 1-A of the present disclosure including theaforementioned various preferred configurations. In relation to theorientation regulating portion on this occasion, a configurationincluding a slit portion provided at the second electrode, aconfiguration including a protruding portion provided at the secondelectrode, or a configuration including a part of the second electrodewith a protruding shape can be employed. The protruding portion isformed of a resist material, for example, and the second electrode isnot formed thereon. In order to provide the part of the second electrodewith a protruding shape, a convex portion may be formed below the secondelectrode, or the part of the second electrode with a protruding shapecan be provided by the same method as a method of forming a concaveportion in the concave and convex portions at the first electrode. It isdesired that a width of the slit portion, the protruding portion, or thepart of the second electrode with the protruding shape be narrower thana width of the convex stem portion. The same can be applied to a liquidcrystal display device according to Mode 2-A of the present disclosureand a liquid crystal display device according to Mode 3 of the presentdisclosure, which will be described later.

Alternatively, it is possible to employ a configuration in which theconcave and convex portions in the liquid crystal display deviceaccording to Mode 1 of the present disclosure are configured by a convexstem portion which is formed in a frame shape at the pixelcircumferential portion and a plurality of branched convex portionswhich extend from the convex stem portion toward the inside of thepixel. In addition, the configuration will be referred to as a “liquidcrystal display device according to Mode 1-B of the present disclosure”for convenience. Here, when an (X, Y) coordinate system in whichstraight lines which pass the pixel center portion and are parallel withthe pixel circumferential portion respectively correspond to an X axisand a Y axis is assumed, in the liquid crystal display device accordingto Mode 1-B of the present disclosure, it is possible to employ aconfiguration in which the plurality of branched convex portionsoccupying a first quadrant extend in parallel with a direction in whicha value of a Y coordinate increases when a value of an X coordinateincreases, the plurality of branched convex portions occupying a secondquadrant extend in parallel with a direction in which a value of a Ycoordinate increases when a value of an X coordinate decreases, theplurality of branched convex portions occupying a third quadrant extendin parallel with a direction in which a value of a Y coordinatedecreases when a value of an X coordinate decreases, and the pluralityof branched convex portions occupying a fourth quadrant extend inparallel with a direction in which a value of a Y coordinate decreaseswhen a value of an X coordinate increases.

In relation to a cross-sectional shape of the convex stem portion whenthe convex stem portion is cut by a virtual vertical plane which isorthogonal to an extending direction of the convex stem portion in theliquid crystal display device according to Mode 1-B of the presentdisclosure including the above preferred form, it is possible to employa configuration with a cross-sectional shape in which a stepped portiondeclines from an external edge of the cross-sectional shape of theconvex stem portion toward an inner edge of the cross-sectional shape ofthe convex stem portion.

Furthermore, in relation to a cross-sectional shape of the branchedconvex portion when the branched convex portion is cut by a virtualvertical plane which is orthogonal to an extending direction of thebranched convex portion in the liquid crystal display device accordingto Mode 1-B of the present disclosure including the aforementionedvarious preferred configurations, it is possible to employ aconfiguration with a cross-sectional shape in which a stepped portiondeclines from the center of the cross-sectional shape of the branchedconvex portion toward an edge of the cross-sectional shape of thebranched convex portion. In relation to a cross-sectional shape of thebranched convex portion when the branched convex portion is cut by avirtual vertical plane which is in parallel with the extending directionof the branched convex portion in the liquid crystal display deviceaccording to Mode 1-B of the present disclosure including theaforementioned various preferred configurations, it is possible toemploy a configuration with a cross-sectional shape in which a steppedportion declines from the cross-sectional shape of the branched convexportion on a side of the convex stem portion toward an end portion ofthe cross-sectional shape of the branched convex portion.

Furthermore, it is possible to employ a configuration in which a slitportion or a protruding portion which passes through a pixel centerportion and is parallel with the pixel circumferential portion is formedat the first electrode in the liquid crystal display device according toMode 1-B of the present disclosure including the aforementioned variouspreferred configuration. The protruding portion is formed of a resistmaterial, for example, and the first electrode is not formed thereon.Alternatively, it is possible to employ a configuration in which aconvex portion with a cross-shape which passes through the pixel centerportion is formed at the first electrode so as to be surrounded by aconcave portion. Such a convex portion with a cross shape can beprovided by forming a convex portion with a cross shape below the firstelectrode or by the same method as a method of forming the concave andconvex portions at the first electrode. Alternatively, it is alsopossible to provide a concave portion with a cross shape which passesthrough the pixel center portion instead of the slit portion or theprotruding portion (rib). The same can be applied to a liquid crystaldisplay device according to Mode 2-B of the present disclosure and aliquid crystal display device according to Mode 4 of the presentdisclosure, which will be described later.

Furthermore, it is also possible to employ a configuration in which aconvex structure is formed from a part of a first substrate positionedbetween pixels and a part of the first substrate corresponding to thepixel circumferential portion and the circumferential portion of theconcave and convex portions are formed on the convex structure in theliquid crystal display device according to Mode 1-A or Mode 1-B of thepresent disclosure including the aforementioned various preferredconfiguration. In addition, it is possible to employ a configuration inwhich the convex structure is formed based on a black matrix formed ofan existing material.

In addition, it is possible to employ a configuration in which theconcave and convex portions are configured by convex stem portions whichpass through the pixel center portion and extend in a cross shape and aplurality of branched convex portions which extend from the convex stemportions toward the pixel circumferential portion. Moreover, such aconfiguration will be referred to as a “liquid crystal display deviceaccording to Mode 2-A of the present disclosure” for convenience. Here,when an (X, Y) coordinate system in which the convex stem portionsextending in the cross shape respectively correspond to an X axis and aY axis is assumed in the liquid crystal display device according to Mode2-A of the present disclosure, it is possible to employ a configurationin which the plurality of branched convex portions occupying a firstquadrant extend in parallel with a direction in which a value of a Ycoordinate increases when a value of an X coordinate increases, theplurality of branched convex portions occupying a second quadrant extendin parallel with a direction in which a value of a Y coordinateincreases when a value of an X coordinate decreases, the plurality ofbranched convex portions occupying a third quadrant extend in parallelwith a direction in which a value of a Y coordinate decreases when avalue of an X coordinate decreases, and the plurality of branched convexportions occupying a fourth quadrant extend in parallel with a directionin which a value of a Y coordinate decreases when a value of an Xcoordinate increases.

In addition, it is possible to employ a configuration in which anorientation regulating portion is formed at a part of a second electrodecorresponding to the convex stem portions in the liquid crystal displaydevice according to Mode 2-A of the present disclosure including theaforementioned preferred configuration. In relation to the orientationregulating portion on this occasion, a configuration including a slitportion provided at the second electrode or a configuration including aprotruding portion provided at the second electrode can be employed.

Alternatively, it is possible to employ a configuration in which theconcave and convex portions are configured by a convex stem portionwhich is formed in a frame shape at the pixel circumferential portionand a plurality of branched convex portions which extend from the convexstem portion toward the inside of pixel. In addition, such aconfiguration will be referred to as a “liquid crystal display deviceaccording to Mode 2-B of the present disclosure” for convenience. Here,when an (X, Y) coordinate system in which straight lines which passthrough the pixel center portion and are in parallel with the pixelcircumferential portions respectively correspond to an X axis and a Yaxis is assumed in the liquid crystal display device according to Mode2-B of the present disclosure, it is possible to employ a configurationin which the plurality of branched convex portions occupying a firstquadrant extend in parallel with a direction in which a value of a Ycoordinate increases when a value of an X coordinate increases, theplurality of branched convex portions occupying a second quadrant extendin parallel with a direction in which a value of a Y coordinateincreases when a value of an X coordinate decreases, the plurality ofbranched convex portions occupying a third quadrant extend in parallelwith a direction in which a value of a Y coordinate decreases when avalue of an X coordinate decreases, and the plurality of branched convexportions occupying a fourth quadrant extend in parallel with a directionin which a value of a Y coordinate decreases when a value of an Xcoordinate increases.

In addition, it is possible to employ a configuration in which a slitportion or a protruding portion which passes through the pixel centerportion and is in parallel with the pixel circumferential portion isformed at the first electrode in the liquid crystal display deviceaccording to Mode 2-B of the present disclosure including theaforementioned preferred configuration.

Furthermore, it is possible to employ a configuration in which theconvex structure is formed based on a black matrix formed of an existingmaterial in the liquid crystal display device according to Mode 2 of thepresent disclosure including the aforementioned various preferredconfigurations.

Moreover, it is possible to employ a configuration in which anorientation regulating portion includes a slit portion provided at asecond electrode or a configuration in which the orientation regulatingportion includes a protruding portion provided at the second electrodein the liquid crystal display device according to Mode 3 of the presentdisclosure.

In addition, it is possible to employ a configuration in which a blackmatrix is formed such that a projected image of a part of a firstsubstrate positioned between pixels and a projected image of the blackmatrix are overlapped or a configuration in which the black matrix isformed such that a projected image of a region from the part of thefirst substrate positioned between the pixels to an end portion ofconcave and convex portions overlap each other in a liquid crystaldisplay device according to Mode 4 of the present disclosure.

It is possible to employ a configuration in which the liquid crystalmolecules have a negative dielectric constant anisotropy in the liquidcrystal display devices according to Modes 1 to 4 of the presentdisclosure including the aforementioned various preferred configurations(hereinafter, they will be collectively and simply referred to as a“liquid crystal display device of the present disclosure” in somecases).

The liquid crystal display device or the liquid crystal display elementof the present disclosure is produced by a process in which the firstelectrode is formed on the first substrate, and a first oriented film isformed on a facing surface of the first substrate, which faces thesecond substrate, and the first electrode, a process in which the secondelectrode is formed on the second substrate, and a second oriented filmis formed on a facing surface of the second substrate, which faces thefirst substrate, and the second electrode, a process in which the firstsubstrate and the second substrate are arranged such that the firstoriented film and the second oriented film face each other, and theliquid crystal layer is sealed between the first oriented film and thesecond oriented film, and a process in which the liquid crystalmolecules are oriented by causing a reaction (crosslink or deformation)of a polymer compound configuring at least the first oriented film whilea predetermined electric field is applied to the liquid crystal layer.

In such a case, it is preferable to apply the electric field to theliquid crystal layer such that the liquid crystal molecules are alignedin an oblique direction with respect to a surface of at least one of thepair of substrates. Basically, an orientation angle (deviation angle) ofthe liquid crystal molecules when a pre-tilt is applied is defineddepending on strength and a direction of the electric field and amolecular structure of a material of the oriented films, and a polarangle (zenithal angle) is defined depending on the strength of theelectric field and the molecular structure of the material of theoriented films.

The pair of substrates are configured by a substrate which includes apixel electrode and a substrate which includes a facing electrode. Forexample, the first substrate may be the substrate which includes thepixel electrode, and the second substrate may be the substrate whichincludes the facing electrode. A color filter layer is formed on theside of the substrate which includes the facing electrode (secondsubstrate), or alternatively, the color filter layer is formed on theside of the substrate which includes the pixel electrode (firstsubstrate). A circuit for driving pixels such as a TFT is provided onthe substrate which includes the pixel electrode (first substrate). Inaddition, the layer which includes the circuit for driving the pixelssuch as the TFT will be referred to as a “TFT layer” in some cases. Whenthe color filter layer is formed on the side of the substrate whichincludes the facing electrode, a flattened layer is formed on the TFTlayer, and the first electrode is formed on the flattened layer. On theother hand, when the color filter layer is formed on the side of thesubstrate which includes the pixel electrode (first substrate), thecolor filter is formed on the TFT layer, and the first electrode isformed on the color filter layer, or on an overcoat layer which isformed on the color filter layer, or on a passivation film formed of aninorganic material. When a pixel is configured by a plurality of subpixels in the liquid crystal display device, the pixel herein can beunderstood as a sub pixel. The first electrode and the second electrodemay be configured by a transparent material such as ITO (indium tinoxide), IZO, ZnO, or SnO. In addition, the second electrode may beformed as a so-called solid electrode (an electrode on which nopatterning is performed). It is possible to exemplify a range from 1micrometer to 20 micrometers, and more preferably a range from 2micrometers to 10 micrometers as widths of the branched convex portionand the concave portion. When the widths of the branched convex portionand the concave portion are less than 1 micrometer, it is difficult toform the branched convex portion and the concave portion, and there is aconcern that a sufficient fabrication yield might not be secured. On theother hand, when the widths of the branched convex portion and theconcave portion exceed 20 micrometers, there is a concern that asatisfactory oblique electric field might not be easily generatedbetween the first electrode and the second electrode when drive voltageis applied to the first electrode and the second electrode. It ispossible to exemplify a range from 2*10⁻⁶ m to 2*10⁻⁵ m, and morepreferably a range from 4*10⁻⁶ to 1.5*10⁻⁵ m as a width of the convexstem portion. It is possible to exemplify a range from 5*10⁻⁸ m to1*10⁻⁶ m, and more preferably a range from 1*10⁻⁷ m to 5*10⁻⁷ m as aheight from the concave portion and the convex portion which is theclosest to the concave portion, and it is possible to exemplify a rangefrom 5*10⁻⁸ m to 1*10⁻⁶ and more preferably a range from 1*10⁻⁷ m to5*10⁻⁷ as a height of each stepped portion in the convex portion (aheight difference between adjacent top surfaces of the convex portionwhich configures the stepped portion). In so doing, it is possible tosatisfactorily control the orientation, secure a sufficient fabricationyield, and prevent a decrease in transmittance and extension of processtime.

EXAMPLE 1

Example 1 relates to a liquid crystal display device according to Mode 1of the present disclosure, and more specifically to a liquid crystaldisplay device according to Mode 1-A of the present disclosure. FIG. 1shows a partial end surface view schematically showing the liquidcrystal display device according to Example 1. FIG. 2 is a planar viewschematically showing the first electrode corresponding to a pixelconfiguring the liquid crystal display device according to Example 1.FIGS. 3A, 3B, and 3C are partial cross-sectional views schematicallyshowing the first electrode and the like taken along the arrowIIIA-IIIA, the arrow IIIB-IIIB, and the arrow IIIC-IIIC in FIG. 2. FIG.3D is a partial cross-sectional view schematically showing a part ofFIG. 3C in an enlarged manner.

The liquid crystal display device according to Example 1 or Examples 2to 9, which will be described later, is a liquid crystal display devicein which a plurality of pixels 10 are aligned such that each of theplurality of pixels 10 includes a first substrate 20 and a secondsubstrate 50, a first electrode (pixel electrode) 140, 240, 340, or 440which is formed on a facing surface of the first substrate 20 whichfaces the second substrate 50, a first oriented film 21 which covers thefirst electrode 140, 240, 340, or 440 and the facing surface of thefirst substrate 20, a second electrode (facing electrode) 160 which isformed on a facing surface of the second substrate 50 which faces thefirst substrate 20, a second oriented film 51 which covers the secondelectrode 160 and the facing surface of the second substrate 50, and aliquid crystal layer 70 which is provided between the first orientedfilm 21 and the second oriented film 51 and includes liquid crystalmolecules 71A, 71B, and 71C. To the liquid crystal molecules, a pre-tiltis applied by at least the first oriented film 21. In addition, theliquid crystal molecules have negative dielectric constant anisotropy.

The liquid crystal molecules 71 can be classified into the liquidcrystal molecules 71A which are held by the first oriented film 21 inthe vicinity of a boundary with the first oriented film 21, the liquidcrystal molecules 71B which are held by the second oriented film 51 inthe vicinity of a boundary with the second oriented film 51, and otherliquid crystal molecules 71C. The liquid crystal molecules 71C arepositioned in an intermediate region in a thickness direction of theliquid crystal layer 70 and aligned such that long axial directions(directors) of the liquid crystal molecules 71C are substantiallyperpendicular to the first substrate 20 and the second substrate 50 in astate in which the drive voltage is turned off. Here, when the drivevoltage is turned on, the directors of the liquid crystal molecules 71Care inclined and oriented so as to be in parallel with the firstsubstrate 20 and the second substrate 50. Such a behavior is caused by acharacteristic of the liquid crystal molecules 71C that the dielectricconstant in the long axial direction is smaller than that in the shortaxial direction. Since the liquid crystal molecules 71A and 71B have thesame characteristic, the liquid crystal molecules 71A and 71B basicallyexhibit the same behavior as that of the liquid crystal molecules 71C inaccordance with a variation in ON and OFF states of the drive voltage.However, a pre-tilt theta₁ is applied to the liquid crystal molecules71A by the first oriented film 21, and the directors thereof are in aposture inclined from a normal direction of the first substrate 20 andthe second substrate 50. Similarly, a pre-tilt theta₂ is applied to theliquid crystal molecules 71B by the second oriented film 51, and thedirectors thereof are in a posture inclined from a normal direction ofthe first substrate 20 and the second substrate 50. In addition, theterm “held” means a state in which the oriented films 21 and 51 and theliquid crystal molecules 71A and 71B are not fixedly adhered to eachother and regulate the orientation of the liquid crystal molecules 71.In addition, the pre-tilt theta (theta₁, theta₂) represents aninclination angle of a director D of the liquid crystal molecule 71(71A, 71B) with respect to a Z direction in a state in which the drivevoltage is turned off when Z represents a direction which isperpendicular to the surfaces of the first substrate 20 and the secondsubstrate 50 (normal direction) as shown in FIG. 26A.

In the liquid crystal layer 70, both the pre-tilt theta₁ and thepre-tilt theta₂ are greater than 0 degrees. In the liquid crystal layer70, the pre-tilt theta₁ and the pre-tilt theta₂ may be the same angle(theta₁=theta₂). However, it is preferable that the pre-tilt theta₁ andthe pre-tilt theta₂ be different angles (theta₁ is not equal to theta₂).In so doing, it is possible to enhance a response speed in response toapplication of the drive voltage than a case in which both the pre-tilttheta₁ and the pre-tilt theta₂ are 0 degrees and obtain substantiallythe same contrast as that in the case in which both the pre-tilt theta₁and the pre-tilt theta₂ are 0 degrees. Accordingly, it is possible toreduce the light transmittance during a black display and enhancecontrast while enhancing the response characteristic. When the pre-tilttheta₁ and the pre-tilt theta₂ are differently set, it is desirable thata greater pre-tilt theta of the pre-tilt theta₁ and the pre-tilt theta₂be 1 degree or more and 4 degrees or less. By setting the greaterpre-tilt theta in the above range, an especially large effect can beachieved.

In addition, a TFT layer 30 (which will be described later in detail) isformed on the first substrate 20, a flattened layer 22 formed of aphotosensitive organic insulating material such as polyimide resin oracrylic resin is formed on the TFT layer 30, and the first electrode140, 240, 340, or 440 is formed on the flattened layer 22. Each ofreference numerals 146 and 246 represents a part of the first substratepositioned between pixels. The flattened layer 22 may be formed of aninorganic insulating material such as SiO₂, SiN, or SiON.

In the liquid crystal display device according to Example 1, a pluralityof concave and convex portions 141 (convex portions 142 and concaveportions 145) are formed on the flattened layer 22, and a plurality ofstepped portions are formed on the convex portions 142 included on thefirst electrode 140.

Specifically, in the liquid crystal display device according to Example1, the concave and convex portions 141 includes convex stem portions(main convex portions) 143 which pass the pixel center portion andextend in a cross shape and a plurality of branched convex portion (subconvex portions) 144 which extend from the convex stem portions 143toward the pixel circumferential portion. More specifically, when an (X,Y) coordinate system in which the convex stem portions 143 extending inthe cross shape respectively corresponds to an X axis and a Y axis isassumed, the plurality of branched convex portions 144 occupying a firstquadrant extend in parallel with a direction in which a value of a Ycoordinate increases when a value of an X coordinate increases, theplurality of branched convex portions 144 occupying a second quadrantextend in parallel with a direction in which a value of a Y coordinateincreases when a value of an X coordinate decreases, the plurality ofbranched convex portions 144 occupying a third quadrant extend inparallel with a direction in which a value of a Y coordinate decreaseswhen a value of an X coordinate decreases, and the plurality of branchedconvex portions 144 occupying a fourth quadrant extend in parallel witha direction in which a value of a Y coordinate decreases when a value ofan X coordinate increases.

In addition, a cross-sectional shape of the convex stem portion 143 whenthe convex stem portion 143 is cut by a virtual vertical plane which isorthogonal to an extending direction of the convex stem portion 143 is across-sectional shape in which the stepped portion declines from thecenter of the cross-sectional shape of the convex stem portion 143toward the edge of the cross-sectional shape of the convex stem portion143. Specifically, the top surface of the convex stem portion 143 isconfigured by a top surface 143B at the center of the convex stemportion 143 and a top surface 143A positioned on both sides of the topsurface 143B. When two stepped portions are present in the convex stemportion 143 as described above, and the concave portion 145 is regardedas a reference, the top surface 143A and the top surface 143B are higherin this order. The top surface of the branched convex portion 144 isrepresented by a reference numeral 144A, and the top surface 143A of theconvex stem portion 143 and the top surface 144A of the branched convexportion 144 are in the same level. In the drawing, the top surface plane143B of the convex stem portion 143 is hatched in the horizontaldirection, and the concave portion 145 is hatched in the verticaldirection.

The stepped portion of the convex stem portion or the branched convexportion, which will be described later, can be obtained by (a) forming aresist material layer on a flattened layer as a base (or a color filterlayer which will be described later) (the flattened layer and the colorfilter layer will be collectively referred to as “flattened layer andthe like”), (b) forming the concave and convex portions in the resistmaterial layer by exposure and development, (c) forming the concave andconvex portions in the flattened layer and the like by etching back ofthe resist material layer and the flattened layer and the like, and (d)forming and patterning of a transparent conductive material layer on theflattened layer and the like, for example.

Alternatively, the stepped portion of the convex stem portion or thebranched convex portion, which will be described later, can be obtainedby (a) forming a resist material layer on a base layer formed on theflattened layer and the like, (b) forming the concave and convex portionin the resist material layer by exposure and development, (c) formingthe concave and convex portion in the base layer by etching back theresist material layer and the flattened layer and the like, and (d)forming and patterning a transparent conductive material layer on thebase layer, for example.

Alternatively, the stepped portion of the convex stem portion or thebranched convex portion, which will be described later, can be obtainedby (a) forming an insulating material layer which is patterned on theflattened layer and the like as a base and (b) forming and patterning atransparent conductive material layer on the flattened layer and thelike and the insulating material layer, for example.

Alternatively, the stepped portion of the convex stem portion or thebranched convex portion, which will be described later, can be obtainedby (a) forming a transparent conductive material layer on the flattenedlayer and the like as a base, (b) forming a resist material layer on thetransparent conductive material layer, (c) forming the concave andconvex portions in the resist material layer by exposure anddevelopment, and (d) etching back of the resist material layer and thetransparent conductive material layer, for example.

Alternatively, the stepped portion of the convex stem portion or thebranched convex portion, which will be described later, can be obtainedby (a) forming and patterning a first transparent conductive materiallayer (see a reference numeral 140A in FIGS. 3A and 3B) in the flattenedlayer as a base and (b) forming and patterning of a second transparentconductive material layer (see a reference numeral 140B in FIGS. 3A and3B) with etching selectivity with the first transparent conductivematerial layer on the first transparent conductive material layer, forexample.

Alternatively, the stepped portion of the convex stem portion or thebranched convex portion, which will be described later, can be obtainedby optimizing a thickness of the flattened layer and thereby forming aconvex portion on the flattened layer by an influence of a thickness ofcomponents of the liquid crystal display device (various signal lines,auxiliary capacity electrodes, a gate electrode, source/drainelectrodes, and various kinds of wiring, for example) formed on or abovethe first substrate.

The side surface of the convex stem portion or the branched convexportion, which will be described later, may be a vertical surface orregularly or reversely tapered.

The above descriptions relating to the convex stem portion and thebranched convex portion can be applied to other examples.

FIG. 27 shows a circuit configuration in the liquid crystal displaydevice shown in FIG. 1 or a liquid crystal display device according toExamples 2 to 9 which will be described later.

As shown in FIG. 27, the liquid crystal display device includes a liquidcrystal display element which includes a plurality of pixels 10 providedin a display region 80. According to the liquid crystal display device,a source drive 81, a gate driver 82, a timing controller 83 whichcontrols the source driver 81 and the gate driver 82, and a powercircuit 84 which supplies power to the source driver 81 and the gatedriver 82 are provided in the circumference of the display region 80.

The display region 80 is a region in which a video image is displayed,namely a region which is configured to be capable of displaying a videoimage by aligning the plurality of pixels 10 in a matrix shape. Inaddition, FIG. 27 also shows a region corresponding to four pixels 10 inan enlarged manner as well as the display region 80 including theplurality of pixels 10.

In the display region 80, a plurality of source lines 91 are aligned ina row direction, a plurality of gate lines 92 are aligned in a columndirection and pixels 10 are respectively arranged at positions at whichthe source lines 91 intersect the gate lines 92. Each of the pixels 10is configured so as to include a TFT 93 and a capacitor 94 as well asthe first electrode 140 and the liquid crystal layer 70. At each TFT 93,a source electrode is connected to the source line 91, a gate electrodeis connected to the gate line 92, and a drain electrode is connected tothe capacitor 94 and the first electrode 140. Each source line 91 isconnected to the source driver 81, and an image signal is suppliedthereto from the source driver 81. Each gate line 92 is connected to thegate driver 82, and a scanning signal is sequentially supplied theretofrom the gate driver 82.

The source driver 81 and the gate driver 82 select a specific pixel 10from among the plurality of pixels 10.

The timing controller 83 outputs image signals (various video signal ofRGB corresponding to red, green, and blue, for example) and a sourcedriver control signal for controlling operations of the source diver 81,for example, to the source diver 81. In addition, the timing controller83 outputs a gate driver control signal for controlling operations ofthe gate driver 82, for example, to the gate driver 82. Examples of thesource diver control signals include a horizontal synchronizationsignal, a start pulse signal, and a clock signal for the source driver.Examples of the gate driver signals include a vertical synchronizationsignal and a clock signal for the gate driver.

In fabricating the liquid crystal display device according to Example 1,the first oriented film 21 is firstly formed on the surface of the firstsubstrate 20, and the second oriented film 51 is formed on the surfaceof the second substrate 50. Specifically, the first substrate 20 isfirstly fabricated by providing the first electrode 140 in a matrixshape, for example, on the surface of the first substrate 20. Inaddition, the second substrate 50 is fabricated by providing the secondelectrode 160 on a color filter of the second substrate 50 with thecolor filter formed thereon.

Then, a material of the oriented film is applied or printed on each ofthe first electrode 140 and the second electrode 160, and a heattreatment is then performed thereon. A temperature of the heatingtreatment is preferably 80 degrees Celsius or higher and more preferably150 degrees Celsius or higher and 200 degrees Celsius or lower. Inaddition, the heat treatment may be performed while the heatingtemperature is changed in a stepwise manner. In so doing, solventcontained in the applied or printed material of the oriented filmevaporates, and the oriented films 21 and 52 containing polymercompounds are formed. Thereafter, a treatment such as rubbing may beperformed thereon as necessary.

Next, the first substrate 20 and the second substrate 50 are arrangedsuch that the oriented film 21 and the oriented film 51 face each other,and the liquid crystal layer 70 containing the liquid molecules 71 issealed between the oriented film 21 and the oriented film 51.Specifically, spacer protrusions such as plastic beads for securing acell gap are dispersed on the surface, on which the oriented film 21 or51 is formed, of one of the first substrate 20 and the second substrate50, and a sealing portion is printed by using an epoxy adhesive agent orthe like by a screen printing method, for example. Thereafter, the firstsubstrate 20 and the second substrate 50 are adhered via the spacerprotrusions and the sealing portion such that the oriented films 21 and51 face each other, and a liquid crystal material containing the liquidcrystal molecules 71 is poured therebetween. Then, the liquid crystalmaterial is sealed between the first substrate 20 and the secondsubstrate 50 by hardening the sealing portion by heating, for example.

Then, voltage is applied between the first electrode 140 and the secondelectrode 160 by using a voltage applying unit. Voltage of 3 volts to 30volts is applied, for example. In so doing, an electric field(electrical field) in a direction at a predetermined angle with respectto the surfaces of the first substrate 20 and the second substrate 50 isgenerated, and the liquid crystal molecules 71 are oriented so as toincline in a predetermined direction from a vertical direction of thefirst substrate 20 and the second substrate 50. That is, the orientationangle (deviation angle) of the liquid crystal molecules 71 at this timeis defined depending on strength and a direction of the electric fieldand a molecular structure of the material of the oriented films, and apolar angle (zenithal angle) is defined depending on the strength of theelectric field and the molecular structure of the material of theoriented films. Therefore, it is possible to control values of thepre-tilt theta₁ and the pre-tilt theta₂ of the liquid crystal molecules71A and 71B by appropriately adjusting the voltage.

Furthermore, the oriented films 21 and 51 are irradiated with an energyline (specifically, ultraviolet ray (UV)) from the outside of the firstsubstrate 20, for example, while the voltage is applied. That is, theliquid crystal layer is irradiated with an ultraviolet ray while anelectric field or a magnetic field is applied thereto so as to align theliquid crystal molecules 71 in an oblique direction with respect to thesurfaces of the pair of substrates 20 and 50. In so doing, across-linkable functional group or a polymerizable functional groupcontained in the polymer compounds in the oriented films 21 and 51 ismade to react to cause a cross-link. In so doing, the polymer compoundsmemorize a direction in which the liquid crystal molecules 71 are torespond and the pre-tilt is applied to the liquid crystal molecules 71in the vicinity of the oriented films 21 and 51. As a result, thepre-tilt theta₁ and the pre-tilt theta₂ are applied to the liquidcrystal molecules 71A and 71B positioned in the vicinity of theboundaries with the oriented films 21 and 51 in the liquid crystal layer70 in a non-driven state. As the ultraviolet ray (UV), an ultravioletray which contains many optical components with a wavelength from about295 nm to about 365 nm is preferable. If an ultraviolet ray whichcontains many optical components in a shorter wavelength band thanpreferable is used, there is a concern that the liquid crystal molecules71 photodegrade and deteriorate. Although the irradiation with theultraviolet ray (UV) is performed from the outside of the firstsubstrate 20 in the above description, the irradiation may be performedfrom the outside of the second substrate 50 or may be performed from theoutside of both the first substrate 20 and the second substrate 50. Insuch a case, it is preferable that the irradiation with the ultravioletray (UV) be performed from the side of the substrate with highertransmittance. In addition, when the irradiation with the ultravioletray (UV) is performed from the outside of the second substrate 50, thereis a concern that the ultraviolet ray is absorbed by the color filterdepending on a wavelength band of the ultraviolet ray (UV) and thecross-link reaction might not be easily caused. For this reason, it ispreferable to perform the irradiation from the outside of the firstsubstrate 20 (the side of the substrate which includes the pixelelectrode).

It is possible to complete the liquid crystal display device (liquidcrystal display element) shown in FIG. 1 by the above processes.

For operating the liquid crystal display device (liquid crystal displayelement), the orientation state of the liquid crystal molecules 71included in the liquid crystal layer 70 changes in accordance with apotential difference between the first electrode 140 and the secondelectrode 160 in the selected pixel 10 when the drive voltage isapplied. Specifically, the liquid crystal molecules 71A and 71Bpositioned in the vicinity of the oriented films 21 and 51 lie down intheir own inclination directions and the operations are propagated tothe other liquid crystal molecules 71C in the liquid crystal layer 70 inresponse to the application of the drive voltage from the state beforethe application of the drive voltage, which is shown in FIG. 1. As aresult, the liquid crystal molecules 71 respond by taking a posture inwhich the liquid crystal molecules are substantially horizontal(parallel) with the first substrate 20 and the second substrate 50. Inso doing, an optical characteristic of the liquid crystal layer 70changes, incident light on the liquid crystal display element is changedinto a modulated outgoing light, and a video image is displayed bygradation expression on the basis of the outgoing light.

In the liquid crystal display device, a video image is displayed byapplying drive voltage between the first electrode (pixel electrode) 140and the second electrode (facing electrode) 160 as follows.Specifically, the source driver 81 supplies an individual image signalto a predetermined source line 91 based on an image signal input fromthe timing controller 83 in response to an input of a source divercontrol signal which is similarly sent from the timing controller 83. Inaddition, the gate driver 82 sequentially supplies scanning signals tothe gate line 92 at predetermined timing in response to an input of agate driver control signal from the timing controller 83. In so doing, apixel 10 positioned at an intersection between the source line 91 towhich the image signal is supplied and the gate line 92 to which thescanning signal is supplied is selected, and the drive voltage isapplied to the pixel 10.

Specifically, the TFT is formed based on a method described below, andfurther, a transparent conductive material layer formed of ITO with anaverage film thickness of 2.5 micrometers is formed on the facingsurface of the first substrate 20 on which the flattened layer 22 hasbeen formed. In addition, the first substrate 20 is formed of a glasssubstrate with a thickness of 0.7 mm

That is, a gate electrode 31 is formed on an insulating film 20 formedon the first substrate 20, and a gate insulating layer 32 is formed onthe gate electrode 31 and the insulating film 20′. The gate insulatinglayer 32 is formed of SiO₂, SiN, SiON, or metal oxide, for example.Next, a semiconductor layer 33 as a channel formation region is formedon the gate insulating layer 32, and source/drain electrodes 34 are thenformed on the semiconductor layer 33. The semiconductor layer 33 isformed of polysilicon or amorphous silicon, and the source/drainelectrodes 34 are formed of metal films of titanium, chromium, aluminum,molybdenum, tantalum, tungsten, copper, or the like, or an alloy film ora laminated film thereof. As described above, the TFT layer 30 can beobtained. The above formation of the TFT layer 30 can be performed basedon an existing method. In addition, the TFT is not limited to such aso-called bottom-gate/top-contact type, and can be a bottom-gate/bottomcontact type, a top-gate/top-contact type, or a top-gate/bottom contacttype. Then, the flattened layer 22 is formed over the entire surface,and a connection hole 35 is then formed on the flattened layer 22 aboveone of the source/drain electrodes 34. Then, a conductive material layerfor forming the first electrode 140 is formed on the flattened layer 22including the connection hole 35 (see FIG. 28A).

Then, the resist material layer is formed on the transparent conductivematerial layer, and the concave and convex portions are then formed onthe resist material layer by performing an exposure and thendevelopment. Then, it is possible to form the concave and convexportions 141 (the convex stem portion 143, the branched convex portion144, and the concave portion 145) by etching back the resist materiallayer and the transparent conductive material layer. Thereafter, atransparent conductive material layer formed of ITO with a thickness of0.1 micrometers is formed on the entire surface. Specifications of theconvex stem portion 143, the branched convex portion 144, and theconcave portion 145 are as shown in Tables 1 and 2 below. Next, spacerprotrusions (photosensitive acrylic resin PC-335 manufactured by JSRCorporation) with a size of 3.0 micrometers are formed on the firstelectrode 140. Meanwhile, a color filter is formed on the secondsubstrate 50 formed of a glass substrate with a thickness of 0.7 mm, andthe second electrode 160 which is a so-called solid electrode is formedon the color filter.

[Table 1]

Height Difference between Top Surface 143A of Convex Stem Portion 143and Concave Portion 145: 0.20 micrometers on Average

Height Difference between Top Surface 144A of Branched Convex Portion144 and Concave Portion 145: 0.20 micrometers on Average

Width of Convex Stem Portion 143 (Width of Top Surface 143A of ConvexStem Portion 143): 8.0 micrometers

Width of Top Surface 143B of Convex Stem Portion 143: 4.0 micrometers

Width of Branched Convex Portion 144 (Width of Top Surface 144A ofBranched Convex Portion 144): 2.5 micrometers

Interval between Branched Convex Portion 144 and Branched Convex Portion144 (Space): 2.5 micrometers

[Table 2]

Height Difference between Top Surface 143B and Top Surface 143A ofConvex Stem Portion 143

Example 1-A: 0.10 micrometers on Average

Example 1-B: 0.20 micrometers on Average

Example 1-C: 0.30 micrometers on Average

Example 1-D: 0.60 micrometers on Average

Thereafter, the first oriented film 21 is formed on the first electrode140, and the second oriented film 51 is formed on the second substrate160. Specifically, JALS2131-R6 manufactured by JSR Corporation is usedas a material of the vertical oriented films for the first oriented film21 and the second oriented film 51, and the material of the verticaloriented films is coated on the first electrode 140 and the secondelectrode 160 based on a spin coating method. Then, a drying process at80 degrees Celsius is performed on a hot plate for 80 minutes, baking at200 degrees Celsius is performed in a clean oven in a nitrogenatmosphere for 60 minutes, and the first oriented film 21 and the secondoriented film 51 are obtained.

Then, a sealing portion is formed at an outer edge on the secondsubstrate 50 by applying ultraviolet curable resin containing silicaparticles with a particle diameter of 3.5 micrometers, and a liquidcrystal material which is obtained by mixing 0.3% by mass of acrylicmonomer (A-BP-2E manufactured by Shin-Nakamura Chemical Co., Ltd.) witha negative liquid crystal is dripped into a part surrounded by thesealing portion. Such a fabrication scheme of the liquid crystal displaydevice is called a PSA scheme (Polymer Stabilized Alignment scheme).Thereafter, the first substrate 20 and the second substrate 50 areadhered to each other, and the sealing portion is cured. Subsequently,heating is performed thereon in an oven at 120 degrees Celsius for onehour to completely cure the sealing portion. In so doing, the liquidcrystal layer 70 is sealed, and the liquid crystal cell can becompleted. In addition, an FPA scheme (Field-induced Photo-reactiveAlignment scheme) in which a negative liquid crystal is injected andsealed after an oriented film with a function of memorizing the pre-tiltis applied on at least one electrode may also be employed.

Thereafter, the thus fabricated liquid crystal cell is uniformlyirradiated with ultraviolet rays of 10 J (measured at a wavelength 360nm) while an alternating electric field (60 Hz) of a rectangular wave ateffective voltage of 7 volts is applied, and the polymer compounds inthe oriented films 21 and 51 are made to react. In addition, an obliqueelectric field is applied to the first substrate 20 and the secondsubstrate 50 by the concave and convex portions 141 formed on theflattened layer 22. As described above, the liquid crystal displaydevice (liquid crystal display element) shown in FIG. 1, in which theliquid crystal molecules 71A on the sides of the first substrate 20 andthe second substrate 50 incline at the pre-tilt can be completed.Finally, a pair of polarizing plates (not shown) are attached to theoutside of the liquid crystal display device such that the absorptionaxes intersect each other.

In addition, the liquid crystal display devices according to Examples 2to 9, which will be described later, can be manufactured bysubstantially the same methods.

Meanwhile, a liquid crystal display device in which a stepped portion isnot formed on the convex portion included on the first electrode whilethe plurality of concave and convex portions are included on the firstelectrode, namely a liquid crystal display device provided with a firstelectrode in which the convex stem portion 143 is configured only by thetop surface 143A is manufactured as a liquid crystal display deviceaccording to a Comparative Example.

Characteristics of the thus obtained liquid crystal display devicesaccording to Example 1 and Comparative Example were evaluated. Inaddition, transmission was evaluated based on a simulation by athree-dimensional liquid crystal director, electric field, and opticalcomputation software (LCD Master 3DFEM Version 7.31 manufactured bySintec Inc.). In the simulation, a simulation result of the liquidcrystal display device according to Comparative example was regarded asa reference, and only a parameter for a designed part, the transmittanceof which has been improved as compared with the reference, was changedand studied. The results of the transmittance improved rate when voltageof 7.5 V was applied will be shown in Table 3. In addition, imagesshowing transmittance simulation results in Examples 1-A, 1-B, 1-C, 1-D,and 8 and Comparative example will be shown in FIGS. 29A, 29B, 29C, 30A,30B, and 30C. As compared with a width of a dark line (a part in whichan amount of light transmission is locally small) by the liquid crystaldisplay device according to Comparative Example shown in FIG. 30C,widths of dark lines in Examples 1-A, 1-B, 1-C, 1-D, and 8 are narrower.

[Table 3]

Transmittance Improved Rate

Example 1-A 3.1% Example 1-B 5.0% Example 1-C 4.7% Example 1-D 2.1%Example 8 1.8%

Furthermore, in relation to response speeds, similar values wereobtained for the liquid crystal display devices according to Examples1-A, 1-B, 1-C, and 1-D and Comparative Example. For measuring theresponsive time, LCD 5200 (manufactured by Otsuka Electronics Co., Ltd.)was used to measure time for reaching luminance of 90% of gradation inaccordance with drive voltage from luminance of 10% by applying thedrive voltage (2.5 volts to 7.5 volts) between the first electrode 140and the second electrode 160.

A color filter layer may be formed on the first substrate 20.Specifically, the color filter layer 23 is formed on the TFT layer 30instead of the flattened layer 22 based on an existing method after theTFT layer 30 is formed on the first substrate 20 as described above. Inso doing, a COA (Color Filter On Array) structure can be obtained. Then,a conductive material layer may be formed on the color filter layer 23including the connection hole 35 after the connection hole 35 is formedon the color filter layer 23 above one of the source/drain electrodes 34(see FIG. 28B).

In a liquid crystal display device in the related art, a stepped portionis not formed on the convex stem portion. For this reason, orientationregulating force for the liquid crystal molecules at the center portionof the convex stem portion is weak, and a tilt state of the liquidcrystal molecules at the center portion of the convex stem portion isnot stable as shown in a conceptual diagram in FIG. 4A which shows abehavior of the liquid crystal molecules. On the other hand, since theplurality of stepped portions are formed on the convex stem portion 143in Example 1 as described above, that is, since the plurality of topsurfaces 143A and 143B are formed at the convex stem portion 143, theelectric field is the highest at the center portion of the convex stemportion 143, and the electric field is lowered toward the edge portionof the convex stem portion 143. For this reason, it is possible toenhance the orientation regulating force for the liquid crystalmolecules at the center portion of the convex stem portion 143 andreliably regulate the tilt state of the liquid crystal molecules at thecenter portion of the convex stem portion 143 as shown in a conceptualdiagram in FIG. 4B which shows a behavior of the liquid crystalmolecules. For this reason, it is possible to reliably suppress theoccurrence of the problem that a dark line is generated at a part of animage corresponding to the center portion of the convex stem portion 143during display of the image. That is, it is possible to provide a liquidcrystal display device capable of realizing further a uniform hightransmittance while maintaining a satisfactory voltage responsivecharacteristic, reduce the cost of a light source configuring a backlight and power consumption, and also enhance reliability of the TFT.

EXAMPLE 2

Example 2 is a modification of Example 1. FIG. 5 is a planar viewschematically showing a first electrode corresponding to a pixelconfiguring a liquid crystal display device according to Example 2.FIGS. 7A and 7B are partial cross-sectional views schematically showingthe first electrode and the like taken along the arrow VIIA-VIIA and thearrow VIIB-VIIB in FIG. 5.

In Example 2, a top surface of a convex stem portion 143 is configuredby a top surface 143C at a center portion of the convex stem portion143, a top surface 143B positioned on both sides of the top surface143C, and a top surface 143A positioned outside the top surface 143B.Three stepped portions are present at the convex stem portion 143 asdescribed above, and when a concave portion 145 is regarded as areference, the top surface 143A, the top surface 143B, and the topsurface 143C are higher in this order. In addition, a cross-sectionalshape of the convex stem portion 143 when the convex stem portion 143 iscut by a virtual vertical plane which is in parallel with an extendingdirection of the convex stem portion 143 is a cross-sectional shape inwhich the stepped portion declines from the center portion (the topsurface 143C) of the cross-sectional shape of the convex stem portion143 toward an end portion of the cross-sectional shape of the convexstem portion 143 (the top surface 143B and the top surface 143A). In thedrawing, the top surface 143C is cross-hatched. A height differencebetween the top surface 143C and the top surface 143B of the convex stemportion 143 and a height difference between the top surface 143B and thetop surface 143A is set to 0.20 micrometers on average. Otherspecifications of the convex stem portion 143, the branched convexportion 144, and the concave portion 145 are the same as those in Table1.

Since a configuration and a structure of the liquid crystal displaydevice according to Example 2 can be the same as those of the liquidcrystal display device according to Example 1 other than the abovepoints, detailed description thereof will be omitted.

EXAMPLE 3

Example 3 is also a modification of Example 1. FIG. 6 is a planar viewschematically showing a first electrode corresponding to a pixelconfiguring a liquid crystal display device according to Example 3. FIG.7C is a partial end surface view schematically showing the firstelectrode and the like taken along the arrow XIIC-XIIC in FIG. 6, andFIG. 7D shows a partial end surface view schematically showing a part ofFIG. 7C in an enlarged manner.

In Example 3, a cross-sectional shape of a branched convex portion 144when the branched convex portion 144 is cut by a virtual vertical planewhich is orthogonal to an extending direction of the branched convexportion 144 is a cross-sectional shape in which the stepped portiondeclines from the center of the cross-sectional shape of the branchedconvex portion 144 toward the edge of the cross-sectional shape of thebranched convex portion 144. Specifically, a top surface of the branchedconvex portion 144 is configured by a top surface 144B extending fromthe convex stem portion 143 and a top surface 144A positioned on bothsides of the top surface 144B. Two stepped portions are present at thebranched convex portion 144 as described above, and when the concaveportion 145 is regarded as a reference, the top surface 144A and the topsurface 144B are higher in this order. In the drawing, the top surface144B is hatched in the horizontal direction. In FIGS. 6, 8, and 14, aboundary between the convex stem portion and the branched convex portionis represented by a solid line. A height difference between the topsurface 143B and the top surface 143A of the branched convex portion 144is set to 0.20 micrometers on average. Other specifications of theconvex stem portion 143, the branched convex portion 144, and theconcave portion 145 are the same as those in Table 1. The top surface143B of the convex stem portion 143 and the top surface 144B of thebranched convex portion 144 are in the same level.

Since a configuration and a structure of the liquid crystal displaydevice according to Example 3 can be the same as those of the liquidcrystal display device according to Example 1 other than the abovepoints, detailed description thereof will be omitted.

In addition, the cross-sectional shape of the branched convex portion144 when the branched convex portion 144 is cut by the virtual verticalplane which is in parallel with the extending direction of the branchedconvex portion 144 can also be a cross-sectional shape in which thestepped portion declines from the cross sectional shape of the branchedconvex portion 144 on the side of the convex stem portion toward the endportion of the cross-sectional shape of the branched convex portion 144as shown in FIG. 8 which is a planar view schematically showing thefirst electrode corresponding to a pixel configuring the liquid crystaldisplay device. In addition, a combination with the convex stem portion143 described in Example 2 can also be made as shown in FIG. 9 which isa perspective view schematically showing the first electrodecorresponding to a pixel configuring the liquid crystal display device.

EXAMPLE 4

Although Example 4 is also a modification of Example 1, Example 4relates to a liquid crystal display device according to Mode 1-B of thepresent disclosure. FIG. 10 is a planar view schematically showing afirst electrode corresponding to a pixel configuring the liquid crystaldisplay device according to Example 4, and FIG. 11 is a perspective viewschematically showing the same. FIGS. 13A and 13B are partial endsurface views schematically showing the first electrode and the liketaken along the arrow XIIIA-XIIIA and the arrow XIIIB-XIIIB in FIG. 10,and FIG. 13C is a partial end surface view schematically showing a partof FIG. 13B in an enlarged manner.

Even in the liquid crystal display device according to Example 4, aplurality of concave and convex portions 241 (convex portions 242 andconcave portions 245) are formed in a first electrode 240, and aplurality of stepped portions are formed on the convex portions 242included on the first electrode 240. Specifically, in the liquid crystaldisplay device according to Example 4, the concave and convex portions241 are configured by a convex stem portion (main convex portion) 243which is formed in a frame shape at a pixel circumferential portion anda plurality of branched convex portions (sub convex portions) 244 whichextend from the convex stem portion 243 toward the inside of the pixel.In addition, when an (X, Y) coordinate system in which straight lines inparallel with the pixel circumferential portion respectively correspondto an X axis and a Y axis is assumed in the liquid crystal displaydevice according to Example 4, the plurality of branched convex portions244 occupying a first quadrant extend in parallel with a direction inwhich a value of a Y coordinate increases when a value of an Xcoordinate increases, the plurality of branched convex portions 244occupying a second quadrant extend in parallel with a direction in whicha value of a Y coordinate increases when a value of an X coordinatedecreases, the plurality of branched convex portions 244 occupying athird quadrant extend in parallel with a direction in which a value of aY coordinate decreases when a value of an X coordinate decreases, andthe plurality of branched convex portions 244 occupying a fourthquadrant extend in parallel with a direction in which a value of a Ycoordinate decreases when a value of an X coordinate increases.

In addition, a cross-sectional shape of the convex stem portion 243 whenthe convex stem portion 243 is cut by a virtual vertical plane which isorthogonal to an extending direction of the convex stem portion 243 is across-sectional shape in which the stepped portion declines from anouter edge of the cross-sectional shape of the convex stem portion 243toward an inner edge of the cross-sectional shape of the convex stemportion. Specifically, a top surface of the convex stem portion 243 isconfigured by a top surface 243B in the vicinity of the outer edge ofthe convex stem portion 243 and a top surface 243A in the vicinity ofthe inner edge. Two stepped portions are present at the convex stemportion 243 as described above, and when a concave portion 245 isregarded as a reference, the top surface 243A and the top surface 243Bare higher in this order. In addition, a top surface of the branchedconvex portion 244 will be referred to as a reference numeral 244A, andthe top surface 243A of the convex stem portion 243 and the top surface244A of the branched convex portion 244 are in the same level. In thedrawing, the top surface 243B of the convex stem portion 243 is hatchedin the horizontal direction, and the concave portion 245 is hatched inthe vertical direction. A shape of the concave portion 245 positioned atthe center potion of the pixel is substantially a cross shape.Specifications of the convex stem portion 243, the branched convexportion 244, and the concave portion 243 are as shown in Table 4 below.

[Table 4]

Height Difference between Top Surface 243B and Top Surface 243A ofConvex Stem Portion 243: 0.20 micrometers on Average

Height Difference between Top Surface 243A of Convex Stem Portion 243and Concave Portion 245: 0.20 micrometers on Average

Height Difference between Top Surface 244A of Branched Convex Portion244 and Concave Portion 245: 0.20 micrometers on Average

Width of Convex Stem Portion 243 (Width of Top Surface 243A of ConvexStem Portion 243): 8.0 micrometers

Width of Top Surface 243B of Convex Stem Portion 243: 4.0 micrometers

Width of Branched Convex Portion 244 (Width of Top Surface 244A ofBranched Convex Portion 244): 2.5 micrometers

Interval between Branched Convex Portion 244 and Branched Convex Portion244 (Space): 2.5 micrometers

Width of Cross-Shaped Concave Portion Provided at Center Portion ofPixel: 4.0 micrometers

Since a configuration and a structure of the liquid crystal displaydevice according to Example 4 can be the same as those of the liquidcrystal display device according to Example 1 other than the abovepoints, detailed description thereof will be omitted.

Since the plurality of stepped portions are formed on the convex stemportion 243 in Example 4, the electric field is the highest at the outeredge portion of the convex stem portion 243, and the electric field islowered toward the inner edge portion of the convex stem portion 243. Asa result, it is possible to enhance the orientation regulating force forthe liquid crystal molecules at the convex stem portion 243 and reliablydefine the tilt state of the liquid crystal molecules at the convex stemportion 243. For this reason, it is possible to reliably suppress theoccurrence of the problem that a dark line is generated at a part of animage corresponding to the convex stem portion 243 during display of theimage. That is, it is possible to provide a liquid crystal displaydevice capable of realizing further uniform high transmittance whilemaintaining a satisfactory voltage responsive characteristic, reduce thecost of a light source configuring a back light and power consumption,and also enhance reliability of the TFT.

EXAMPLE 5

Example 5 is a modification of Example 4. FIG. 12 is a planar viewschematically showing a first electrode corresponding a pixelconfiguring a liquid crystal display device according to Example 5, andFIG. 13 is a partial end surface view schematically showing the firstelectrode taken along the arrow XIIID-XIIID in FIG. 12.

In Example 5, a top surface of a convex stem portion 243 is configuredby a top surface 243C in the vicinity of an outer edge of the convexstem portion 243 and a top surface 243B and a top surface 243A locatedtoward an inner edge. Three stepped portions are present at the convexstem portion 243 as described above, and when a concave portion 245 isregarded as a reference, the top surface 243A, the top surface 243B, andthe top surface 243C are higher in this order. In the drawing, the topsurface 243C is cross-hatched. A height difference between the topsurface 243C and the top surface 243B and a height difference betweenthe top surface 243B and the top surface 243A of the convex stem portion243 are set to 0.20 micrometers on average. Other specifications of theconvex stem portion 243, the branched convex portion 244, and theconcave portion 245 are the same as those in Table 4.

Since a configuration and a structure of the liquid crystal displaydevice according to Example 5 can be the same as those of the liquidcrystal display device according to Example 4 other than the abovepoints, detailed description thereof will be omitted.

EXAMPLE 6

Example 6 is a modification of Example 5. FIG. 14 is a planar viewschematically showing a first electrode corresponding to a pixelconfiguring a liquid crystal display device according to Example 6.

In Example 6, a cross-sectional shape of a branched convex portion 244when the branched convex portion 244 is cut by a virtual vertical planewhich is orthogonal to an extending direction of the branched convexportion 244 is a cross-sectional shape in which a stepped portiondeclines from the center of the cross-sectional shape of the branchedconvex portion 244 toward the edge of the cross-sectional shape of thebranched convex portion 244. Specifically, a top surface of the branchedconvex portion 244 is configured by a top surface 244B which extendsfrom a top surface 243B of a convex stem portion 243 and a top surface244A positioned on both sides of the top surface 244B. In addition, whena concave portion 245 is regarded as a reference, two stepped portionsare present at the branched convex portion 244, and the top surface 244Aand the top surface 244B are higher in this order. In the drawing, thetop surface 244B is hatched in the horizontal direction. A heightdifference between the top surface 243B and the top surface 243A of thebranched convex portion 244 is set to 0.28 micrometers on average. Otherspecifications of the convex stem portion 243, the branched convexportion 244, and the concave portion 245 are the same as those in Table4. The top surface 243B of the convex stem portion 243 and the topsurface 244B of the branched convex portion 244 are in the same level.

In addition, it is possible to employ a configuration in which thecross-sectional shape of the branched convex portion 244 when thebranched convex portion 244 is cut by a virtual vertical plane which isin parallel with an extending direction of the branched convex portion244 is a cross-sectional shape in which the stepped portion declinesfrom the cross-sectional shape of the branched convex portion 244 on theside of the convex stem portion toward the end portion of thecross-sectional shape of the branched convex portion 244 as in FIG. 15which is a perspective view schematically showing a modified example ofthe first electrode corresponding to a pixel configuring the liquidcrystal display device according to Example 6.

Since a configuration and a structure of the liquid crystal displaydevice according to Example 6 can be the same as those of the liquidcrystal display device according to Example 4 other than the abovepoints, detailed description thereof will be omitted. In addition, thetop surface of the convex stem portion 243 can be configured by the topsurface 243B and the top surface 243A positioned on both sides of thetop surface 243B in the same manner as in Example 4.

EXAMPLE 7

Example 7 is a modification of the liquid crystal display devicesdescribed in Examples 1 to 6 and relates to a liquid crystal displaydevice according to Mode 2 of the present disclosure. FIG. 16 is aplanar view schematically showing a first electrode corresponding to apixel configuring a liquid crystal display device according to Example7, and an example shown in FIG. 16 is a modification of Example 1.Alternatively, FIG. 17 is a planar view schematically showing a modifiedexample of the first electrode corresponding to a pixel configuring theliquid crystal display device according to Example 7, and a plurality ofstepped portions are not formed in a first electrode 340 while aplurality of concave and convex portions 341 are formed therein. FIG. 18is a partial cross-sectional view schematically showing the firstelectrode and the like taken along the arrow XVIIIA-XVIIIA in FIG. 16.

In the liquid crystal display device according to Example 7, a pluralityof concave and convex portions 141 and 341 are included on the firstelectrodes 140 and 340, a convex structure 147 is formed from a part ofa first substrate positioned between pixel 10 and a pixel 10 to a partof the first substrate corresponding to a pixel circumferential portion,and circumferential portions 141A and 341A of the concave and convexportions 141 and 341 are formed on the convex structure 147.Specifically, the convex structure 147 is formed based on a black matrix147A formed on the color filter layer 23. The black matrix 147A isformed of a photo-curable resin to which carbon has been added. Inaddition, specifications of a convex stem portion 143, a branched convexportion 144, and a convex portion 145 are set as shown in Table 1, and aheight difference between a top surface 143B and a top surface 143A ofthe convex stem portion 143 is set to 0.20 micrometers on average. Inaddition, heights from a flattened layer 22 to end portions of theconcave and convex portions 141 and 341 are 0.3 micrometers on average.

Since the circumferential portions 141A and 341A of the concave andconvex portions 141 and 341 are formed on the convex structure 147 inthe liquid crystal display device according to Example 7, a furtherstrong electric field is generated in the circumferential portion ascompared with a case in which the circumferential portion of the concaveand convex portion is flat. As a result, it is possible to enhance theorientation regulating force for liquid crystal molecules in thecircumferential portions 141A and 341A of the concave portions 141 and341 and reliably define the tilt state of the liquid crystal moleculesat the circumferential portions 141A and 341A of the concave and convexportions 141 and 341. Therefore, it is possible to maintain asatisfactory voltage responsive characteristic.

In addition, the convex structure is not limited to the configuration inwhich the convex portion is formed based on the black matrix and can beconfigured by components of the liquid crystal display device formed onor above the first substrate 20, such as various signal lines, auxiliarycapacity electrodes, a gate electrode, source/drain electrodes, andvarious kinds of wiring. In such a case, it is possible to form theconvex structure in the flattened layer 22 due to an influence of athickness of the components of the liquid crystal display device byoptimizing a thickness of the flattened layer 22.

EXAMPLE 8

Example 8 relates to a liquid crystal display device according to Mode 3of the present disclosure and to modifications of Examples 1 to 3 (theliquid crystal display devices according to Mode 1-A of the presentdisclosure) and a modification of Example 7 (the liquid crystal displaydevice according to Mode 2-A of the present disclosure). FIGS. 19 and 20are partial end surface views schematically showing a liquid crystaldisplay device according to Example 8. In addition, FIGS. 26B and 26Care conceptual diagrams showing behaviors of liquid crystal molecules inthe liquid crystal display device according to Example 8.

In the liquid crystal display device according to Example 8, a pluralityof concave and convex portions 141 are formed in a first electrode 140,and the concave and convex portions 141 are configured by convex stemportions 143 which pass through a pixel center portion and extend in across shape and a plurality of branched convex portions 144 which extendfrom the convex stem portions 143 toward a pixel circumferentialportion, as shown in FIGS. 2, 5, 6, 8, 9, 16, and 17. In addition, asshown in FIG. 19 or 20, an orientation regulating portion 161 is formedat a part of a second electrode 160 corresponding to the convex stemportions 143.

Specifically, the orientation regulating portion 161 is configured by aslit portion 162 with a size of 4.0 micrometers provided at the secondelectrode 160 (see FIGS. 19 and 26B) or configured by a protrudingportion (rib) 163 provided at the second electrode 160 (see FIGS. 20 and26C). More specifically, the protruding portion 163 is formed of anegative photoresist material (Optmer AL manufactured by JSRCorporation) with a width of 1.4 micrometers and a height of 1.2micrometers. In addition, specifications of the convex stem portion 143,the branched convex portion 144, and the concave portion 145 are set asshown in Table 1 below, and a height difference between a top surface143B and a top surface 143A of the convex stem portion 143 is set to0.20 micrometers on average. A planar shape of the slit portion 162 orthe protruding portion (rib) 163 is a cross shape, and a cross-sectionalshape of the protruding portion 163 is an isosceles triangle. The secondelectrode 160 is not formed on the slit portion 162 or the protrudingportion 163.

A characteristic of the liquid crystal display device shown in FIG. 19(see FIG. 17 for a planar view schematically showing a modified exampleof the first electrode corresponding to a pixel), which includes theorientation regulating portion 161 configured by the slit portion 162with a size of 4.0 micrometers provided in the second electrode 160, wasevaluated, and a result shown in Table 3 was obtained. In addition, theliquid crystal display devices according to Example 8 and ComparativeExample exhibited similar responsive speeds.

Since the orientation regulating portion 161 configured by the slitportion 162 is formed at a part of the second electrode 160corresponding to the convex stem portions 143 in the liquid crystaldisplay device according to Example 8, an electric field generated bythe second electrode 160 is deformed in the vicinity of the orientationregulating portion 161. Alternatively, since the orientation regulatingportion 161 configured by the protruding portion (rib) 163 is formed,directions in which the liquid crystal molecules lie down in thevicinity of the protruding portion 163 are defined. As a result, it ispossible to enhance the orientation regulating force for the liquidcrystal molecules in the vicinity of the orientation regulating portion161 and reliably define the tilt state of the liquid crystal moleculesin the vicinity of the orientation regulating portion 161. For thisreason, it is possible to reliably suppress an occurrence of a problemthat a dark line is generated at a part of an image corresponding to theconvex stem portions during display of the image. That is, it ispossible to provide a liquid crystal display device capable of realizingfurther uniform high transmittance while maintaining a satisfactoryvoltage responsive characteristic, reduce the cost of a light sourceconfiguring a back light and power consumption, and also enhancereliability of the TFT. In addition, the orientation regulating portion161 can be configured by a part of the second electrode 160 in aprotruding shape.

EXAMPLE 9

Example 9 relates to a liquid crystal display device according to Mode 4of the present disclosure and to modifications of Examples 4 to 6 (theliquid crystal display devices according to Mode 1-B of the presentdisclosure) and a modification of Example 7 (the liquid crystal displaydevice according to Mode 2-B of the present disclosure). FIGS. 21 and 23are planer views schematically showing a first electrode correspondingto a pixel configuring a liquid crystal display device according toExample 9, and examples shown in FIGS. 21 and 23 are modifications ofExample 4. Alternatively, FIGS. 22 and 24 are planar views schematicallyshowing modified examples of the first electrode corresponding to apixel configuring the liquid crystal display device according to Example9, and a plurality of stepped portions are not included on the firstelectrode 440 while a plurality of concave and convex portions 441 areincluded thereon in the liquid crystal display device. FIGS. 25A and 25Bare partial cross-sectional views schematically showing the firstelectrode and the like taken along the arrow IIXVA-IIXVA and the arrowIIXVB-IIXVB in FIG. 21, and FIGS. 25C and 25D are partialcross-sectional views schematically showing the first electrode and thelike taken along the arrow IIXVC-IIXVC and the arrow IIXVD-IIXVD in FIG.23.

In the liquid crystal display device according to Example 9, a pluralityof concave and convex portions 241 or 441 are formed in a firstelectrodes 240 or 440, the concave and convex portions 241 or 441 areconfigured by convex stem portions 243 or 443 formed in a frame shape ata pixel circumferential portion and a plurality of branched convexportions 244 or 444 which extend from the convex stem portions 243 or443 toward the inside of the pixel. A slit portion 248 or a 448 (seeFIGS. 21 and 23) which passes through a pixel center portion and is inparallel with the pixel circumferential portion or a protruding portion(rib) 249 or 449 (see FIGS. 22 and 24) is formed on the first electrode240 or 440. That is, the slit portion 248 or 448 or the protrudingportion 249 or 449 is formed at a part of a cross-shaped concave portionprovided at the center portion of the pixel. A planar shape of the slitportion 248 or 448 or the protruding portion 249 or 449 is a crossshape. In addition, specifications of the convex stem portion 243, thebranched convex portion 244, and the concave portion 245 are set asshown in Table 4. A width of the slit portion 248 or 448 is set to 4.0micrometers. In addition, a width of the protruding portion 249 or 449formed of a negative photoresist material (Optmer AL manufactured by JSRCorporation) is set to 1.4 micrometers, and a height thereof is set to1.2 micrometers. A cross-sectional shape of the protruding portion 249or 449 is an isosceles triangle. The first electrode 240 or 440 is notformed on the slit portion 248 or 448 or the protruding portion 249 or449.

Since the slit portion or the protruding portion which passes throughthe pixel center portion and is in parallel with the pixelcircumferential portion is formed on the first electrode in the liquidcrystal display device according to Example 9, an electric fieldgenerated by the first electrode is deformed in the vicinity of the slitportion or the protruding portion as compared with a case in which aflat concave portion with no slit portion or protruding portion isformed on the first electrode(when the slit portion is formed), orotherwise, directions in which the liquid crystal molecules lie down aredefined (when the protruding portion is formed). As a result, it ispossible to enhance the orientation regulating force for the liquidcrystal molecules in the vicinity of the slit portion or the protrudingportion and reliably define the tilt state of the liquid crystalmolecules in the vicinity of the slit portion or the protruding portion.For this reason, it is possible to reliably suppress an occurrence of aproblem that a dark line is generated at a part of an imagecorresponding to the convex stem portion during display of the image.That is, it is possible to provide a liquid crystal display devicecapable of realizing further uniform high transmittance whilemaintaining a satisfactory voltage responsive characteristic, reduce thecost of a light source configuring a back light and power consumption,and also enhance reliability of the TFT. In addition, it is possible toemploy a configuration of the protruding portion 249 or 449 in which across-shaped convex portion which passes through the pixel centerportion is formed on the first electrode 240 or 440 so as to besurrounded by a concave portion. Such a cross-shaped convex portion canbe provided by forming a cross-shaped convex portion below the firstelectrode 240 or 440 or can be provide by the same method as the methodof forming the concave and convex portions in the first electrode 240 or440. Alternatively, a cross-shaped concave portion which passes throughthe pixel center portion may be provided instead of the slit portion 248or 448 or the protruding portion (rib) 249 or 449.

Although the above description was given of the present disclosure basedon the preferred examples, the present disclosure is not limited to theexamples, and various modifications can be made. The planar shape of thebranched concave portion is not limited to a V shape described in theexamples, and various patterns in which the branched convex portionextends in a plurality of directions, such as a stripe shape and aladder shape, can be employed. The planar shape of the end portion ofthe branched convex portion when the branched convex portion is viewedas a whole may be a linear shape or a stepped shape. Furthermore, theplanar shape of the end portion of each branched convex portion may be alinear shape, may be configured by a combination of line segments, ormay depict a curve such as a circular arc. In addition, a black matrixmay be formed such that a projected image of a part of the firstsubstrate positioned between pixels and a projected image of the blackmatrix overlap each other from above the end portion of the concave andconvex portion.

Although the description was given of the liquid crystal display device(liquid crystal display element) in a VA mode in the examples, thepresent disclosure is not necessarily limited thereto and can be appliedto other display modes such as an ECB mode (horizontally orientedpositive liquid crystal mode with no twist), an IPS (In Plane Switching)mode, an FFS (Fringe Field Switching) mode, and an OCB (OpticallyCompensated Band) mode. In such cases, the same effects can be achieved.

According to the present disclosure it is possible, however, to achievean especially larger effect of improving a responsive characteristic inthe VA mode than in the IPS mode or the FFS mode as compared with a casein which a pre-tilt treatment is not performed. In addition, althoughthe description was mainly given of the transmission type liquid crystaldisplay device (liquid crystal display element) in the examples, thepresent disclosure is not necessarily limited to the transmission typeand can be applied to a reflection type, for example. In a case of thereflection type, the pixel electrode is formed of an electrode materialwith a light reflectivity, such as aluminum.

In addition, the present disclosure can also be configured as follows.

(1) A liquid crystal display device including: a plurality of alignedpixels, each of which includes a first substrate and a second substrate,a first electrode which is formed on a facing surface of the firstsubstrate facing the second substrate, a first oriented film whichcovers the first electrode and the facing surface of the firstsubstrate, a second electrode which is formed on a facing surface of thesecond substrate facing the first substrate, a second oriented filmwhich covers the second electrode and the facing surface of the secondsubstrate, and a liquid crystal layer which is provided between thefirst oriented film and the second oriented film and includes liquidcrystal molecules, wherein a pre-tilt is applied to the liquid crystalmolecules by at least the first oriented film, wherein a plurality ofconcave and convex portions are included on the first electrode, andwherein a plurality of stepped portions are formed at the convexportions included on the first electrode.

(2) The device according to (1), wherein the concave and convex portionsare configured by convex stem portions which pass through a pixel centerportion and extend in a cross shape and a plurality of branched convexportions which extend from the convex stem portions toward a pixelcircumferential portion.

(3) The device according to (2), wherein a cross-sectional shape of eachconvex stem portion when the convex stem portion is cut by a virtualvertical plane which is orthogonal to an extending direction of theconvex stem portion is a cross-sectional shape in which the steppedportion declines from a center portion of the cross-sectional shape ofthe convex stem portion toward an edge of the cross-sectional shape ofthe convex stem portion.

(4) The device according to any one of (2) and (3), wherein across-sectional shape of each convex stem portion when the convex stemportion is cut by a virtual vertical plane which is in parallel with anextending direction of the convex stem portion is a cross-sectionalshape in which the stepped portion declines from a center portion of thecross-sectional shape of the convex stem portion toward an end portionof the cross-sectional shape of the convex stem portion.

(5) The device according to any one of (2) to (4), wherein across-sectional shape of each branched convex portion when the branchedconvex portion is cut by a virtual vertical plane which is orthogonal toan extending direction of the branched convex portion is across-sectional shape in which the stepped portion declines from acenter of the cross-sectional shape of the branched convex portiontoward an edge of the cross-sectional shape of the branched convexportion.

(6) The device according to any one of (2) to (5), wherein across-sectional shape of each branched convex portion when the branchedconvex portion is cut by a virtual vertical plane which is in parallelwith an extending direction of the branched convex portion is across-sectional shape in which the stepped portion declines from thecross-sectional shape of the branched convex portion on a side of theconvex stem portion toward an end portion of the cross-sectional shapeof the branched convex portion.

(7) The device according to any one of (2) to (6), wherein anorientation regulating portion is formed at a part of the secondelectrode corresponding to the convex stem portions.

(8) The device according to (1), wherein the concave and convex portionsare configured by a convex stem portion which is formed in a frame shapeat a pixel circumferential portion and a plurality of branched convexportions which extend from the convex stem portion toward the inside ofthe pixel.

(9) The device according to (8), wherein a cross-sectional shape of theconvex stem portion when the convex stem portion is cut by a virtualvertical plane which is orthogonal to an extending direction of theconvex stem portion is a cross-sectional shape in which the steppedportion declines from an outer edge of the cross-sectional shape of theconvex stem portion toward an inner edge of the cross-sectional shape ofthe convex stem portion.

(10) The device according to any one of (8) and (9), wherein across-sectional shape of each branched convex portion when the branchedconvex portion is cut by a virtual vertical plane which is orthogonal toan extending direction of the branched convex portion is across-sectional shape in which the stepped portion declines from acenter of the cross-sectional shape of the branched convex portiontoward an edge of the cross-sectional shape of the branched portion.

(11) The device according to any one of (8) to (10), wherein across-sectional shape of each branched convex portion when the branchedconvex portion is cut by a virtual vertical plane which is in parallelwith an extending direction of the branched portion is a cross-sectionalshape in which the stepped portion declines from the cross-sectionalshape of the branched convex portion on a side of the convex stemportion toward an end portion of the cross-sectional shape of thebranched convex portion.

(12) The device according to any one of (8) to (11), wherein a slitportion or a protruding portion which passes through a pixel centerportion and is in parallel with the pixel circumferential portion isformed on the first electrode.

(13) The device according to any one of (2) to (12), wherein a convexstructure is formed from a part of the first substrate positionedbetween pixels and a part of the first substrate corresponding to thepixel circumferential portion, and wherein the circumferential portionof the concave and convex portions are formed on the convex structure.

(14) A liquid crystal display device including: a plurality of alignedpixels, each of which includes a first substrate and a second substrate,a first electrode which is formed on a facing surface of the firstsubstrate facing the second substrate, a first oriented film whichcovers the first electrode and the facing surface of the firstsubstrate, a second electrode which is formed on a facing surface of thesecond substrate facing the first substrate, a second oriented filmwhich covers the second electrode and the facing surface of the secondsubstrate, and a liquid crystal layer which is provided between thefirst oriented film and the second oriented film and includes liquidcrystal molecules, wherein a pre-tilt is applied to the liquid crystalmolecules by at least the first oriented film, wherein a plurality ofconcave and convex portions are included on the first electrode, whereina convex structure is formed from a part of the first substratepositioned between pixels to a part of the first substrate correspondingto a pixel circumferential portion, and wherein a circumferentialportion of the concave and convex portions are formed on the convexstructure.

(15) The device according to (14), wherein the concave and convexportions are configured by convex stem portions which pass through apixel center portion and extend in a cross shape and a plurality ofbranched convex portions which extend from the convex stem portionstoward a pixel circumferential portion.

(16) The device according to (15), wherein an orientation regulatingportion is formed at a part of the second electrode corresponding to theconvex stem portions.

(17) The device according to (14), wherein the concave and convexportions are configured by a convex stem portion which is formed in aframe shape at a pixel circumferential portion and a plurality ofbranched convex portions which extend from the convex stem portiontoward the inside of the pixel.

(18) The device according to (17), wherein a slit portion or aprotruding portion which passes through a pixel center portion and is inparallel with the pixel circumferential portion is formed on the firstelectrode.

(19) A liquid crystal display device including: a plurality of alignedpixels, each of which includes a first substrate and a second substrate,a first electrode which is formed on a facing surface of the firstsubstrate facing the second substrate, a first oriented film whichcovers the first electrode and the facing surface of the firstsubstrate, a second electrode which is formed on a facing surface of thesecond substrate facing the first substrate, a second oriented filmwhich covers the second electrode and the facing surface of the secondsubstrate, and a liquid crystal layer which is provided between thefirst oriented film and the second oriented film and includes liquidcrystal molecules, wherein a pre-tilt is applied to the liquid crystalmolecules by at least the first oriented film, wherein a plurality ofconcave and convex portions are included on the first electrode, whereinthe concave and convex portions are configured by convex stem portionswhich pass through a pixel center portion and extend in a cross shapeand a plurality of branched convex portions which extend from the convexstem portions toward a pixel circumferential portion, and wherein anorientation regulating portion is formed at a part of the secondelectrode corresponding to the convex stem portions.

(20) A liquid crystal display device including: a plurality of alignedpixels, each of which includes a first substrate and a second substrate,a first electrode which is formed on a facing surface of the firstsubstrate facing the second substrate, a first oriented film whichcovers the first electrode and the facing surface of the firstsubstrate, a second electrode which is formed on a facing surface of thesecond substrate facing the first substrate, a second oriented filmwhich covers the second electrode and the facing surface of the secondsubstrate, and a liquid crystal layer which is provided between thefirst oriented film and the second oriented film and includes liquidcrystal molecules, wherein a pre-tilt is applied to the liquid crystalmolecules by at least the first oriented film, wherein a plurality ofconcave and convex portions are included on the first electrode, whereinthe concave and convex portions are configured by a convex stem portionwhich is formed in a frame shape at a pixel circumferential portion anda plurality of branched convex portions which extend from the convexstem portion toward the inside of the pixel, and wherein a slit portionor a protruding portion which passes through a pixel center portion andis in parallel with the pixel circumferential portion is formed on thefirst electrode.

(21) A liquid crystal display device comprising: a first substrate; asecond substrate; a first electrode formed on a first surface of thefirst substrate, the first surface facing the second substrate, thefirst electrode including a plurality of convex and concave portions; afirst oriented film formed on the first surface of the first substrate;a second electrode formed on a second surface of the second substrate,the second surface facing the first substrate; and a liquid crystallayer provided between the first substrate and the second substrate,wherein at least one of the convex portions includes a plurality ofstepped portions.

(22) The liquid crystal display device according to (21), wherein theplurality of convex and concave portions includes convex stem portionsthat pass a pixel center portion and extend in a cross shape and aplurality of branched convex portions that extend from the convex stemportions toward a pixel circumferential portion.

(23) The liquid crystal display device according to (22), wherein theplurality of stepped portions are provided at the convex stem portions,each of the plurality of stepped portions comprising a first surfacepositioned at a center portion of one of the convex stem portions, asecond surface positioned on both sides of the first surface, and athird surface positioned outside the second surface, and wherein aheight of the first surface is greater than a height of the secondsurface, and a height of the second surface is greater than a height ofthe third surface.

(24) The liquid crystal display device according to (22), wherein theplurality of stepped portions are provided at the branched convexportions, each of the plurality of stepped portions comprising a firstsurface extending from one of the convex stem portions and a secondsurface positioned on both sides of the first surface, and wherein aheight of the first surface is greater than a height of the secondsurface.

(25) The liquid crystal display device according to (24), wherein eachof the plurality of stepped portions declines from a side of one of theconvex stem portions toward an end portion of one of the branched convexportions.

(26) The liquid crystal display device according to (21), wherein theconvex and concave portions comprise a convex stem portion formed in aframe shape at a pixel circumferential portion and a plurality ofbranched convex portions that extend from the convex stem portion towardthe inside of a pixel.

(27) The liquid crystal display device according to (26), wherein theconvex stem portion comprises a first surface located at an outer edgeof the convex stem portion, a third surface located at an inner edge ofthe convex stem portion, and a second surface located between the firstand third surfaces, and wherein a height of the first surface is greaterthan a height of the second surface, and a height of the second surfaceis greater than a height of the third surface.

(28) The liquid crystal display device according to (26), wherein eachof the branched convex portions comprises a first surface that extendsfrom a surface of the convex stem portion, and a second surfacepositioned on both sides of the first surface, and wherein a height ofthe first surface is greater than a height of the second surface.

(29) A liquid crystal display device comprising: a first substrate; asecond substrate; a first electrode formed on a first surface of thefirst substrate, the first surface facing the second substrate, thefirst electrode including a plurality of convex and concave portions; afirst oriented film formed on the first surface of the first substrate;a second electrode formed on a second surface of the second substrate,the second surface facing the first substrate; and a liquid crystallayer provided between the first substrate and the second substrate,

wherein a convex structure is formed from a part of the first substratepositioned between pixels to a part of the first substrate correspondingto a pixel circumferential portion, and

wherein a circumferential portion of the concave and convex portions isformed on the convex structure.

(30) The liquid crystal display device according to (29), wherein theconvex structure comprises a black matrix formed on a color filterlayer.

(31) The liquid crystal display device according to (29), wherein theplurality of convex and concave portions includes convex stem portionsthat pass a pixel center portion and extend in a cross shape, wherein aplurality of stepped portions are provided at the convex stem portions,each of the plurality of stepped portions comprising a first surfacepositioned at a center portion of one of the convex stem portions and asecond surface positioned on both sides of the first surface, andwherein a height of the first surface is greater than a height of thesecond surface.

(32) A liquid crystal display device comprising: a first substrate; asecond substrate; a first electrode formed on a first surface of thefirst substrate, the first surface facing the second substrate, thefirst electrode including a plurality of convex and concave portions; afirst oriented film formed on the first surface of the first substrate;a second electrode formed on a second surface of the second substrate,the second surface facing the first substrate; and a liquid crystallayer provided between the first substrate and the second substrate,

wherein the convex and concave portions are configured by convex stemportions that pass through a pixel center portion and extend in a crossshape and a plurality of branched convex portions that extend from theconvex stem portions toward a pixel circumferential portion, andwherein an orientation regulating portion is formed at a part of thesecond electrode corresponding to the convex stem portions.

(33) The liquid crystal display device according to (32), wherein theorientation regulating portion comprises a slit provided at the secondelectrode.

(34) The liquid crystal display device according to (32), wherein theorientation regulating portion comprises a protrusion provided at thesecond electrode.

(35) A liquid crystal display device comprising: a first substrate; asecond substrate; a first electrode formed on a first surface of thefirst substrate, the first surface facing the second substrate, thefirst electrode including a plurality of convex and concave portions; afirst oriented film formed on the first surface of the first substrate;a second electrode formed on a second surface of the second substrate,the second surface facing the first substrate; and a liquid crystallayer provided between the first substrate and the second substrate,

wherein the convex and concave portions are configured by a convex stemportion that is formed in a frame shape at a pixel circumferentialportion and a plurality of branched convex portions that extend from theconvex stem portion toward the inside of a pixel,wherein at least one of a slit portion and a protruding portion isformed on the first electrode, andwherein the at least one of a slit portion and a protruding portionpasses through a pixel center portion and is in parallel with the pixelcircumferential portion.

(36) The liquid crystal display device according to (35), wherein theslit portion is formed on the first electrode, passes through a pixelcenter portion and is in parallel with the pixel circumferentialportion.

(37) The liquid crystal display device according to (35), wherein theprotruding portion is formed on the first electrode, passes through apixel center portion and is in parallel with the pixel circumferentialportion.

(38) A method of manufacturing a liquid crystal display devicecomprising: forming a first oriented film on a first electrode, thefirst electrode formed on a first surface of a first substrate; forminga second oriented film on a second electrode, the second electrodeformed on a second surface of a second substrate, the second orientedfilm facing the first oriented film; sealing a liquid crystal layerbetween the first and second oriented films; applying a voltage betweenthe first and second electrodes; and irradiating the first and secondoriented films with an ultraviolet ray while applying the voltage.

(39) The method according to (38), comprising performing a heattreatment on each of the first and second oriented films.

It should be understood that various changes and modifications to thepresently preferred embodiments described herein will be apparent tothose skilled in the art. Such changes and modifications can be madewithout departing from the spirit and scope of the present subjectmatter and without diminishing its intended advantages. It is thereforeintended that such changes and modifications be covered by the appendedclaims.

REFERENCE SIGNS LIST

-   10, 10A, 10B, 10C: pixel-   20: first substrate-   21: first oriented film-   22: flattened film-   23: color filter layer-   30: TFT layer-   31: gate electrode-   32: gate insulating layer-   33: semiconductor layer (channel formation region)-   34: source/drain electrodes-   35: connection hole-   50: second substrate-   51: second oriented film-   70: liquid crystal layer-   71A, 71B, 71C: liquid crystal molecules-   80: display region-   81: source driver-   82: gate driver-   83: timing controller-   84: power circuit-   91: source line-   92: gate line-   93: TFT-   94: capacitor-   140, 240, 340, 440: first electrode-   140A: first transparent conductive material layer-   140B: second transparent conductive material layer-   141, 241, 341, 441: concave and convex portion-   141A, 341A: circumferential portion of concave and convex portion-   142, 242: convex portion-   143, 243, 443: convex stem portion (main convex portion)-   143A, 143B, 143C, 243A, 243B; top surface of convex stem portion-   144, 244, 444: branched convex portion (sub convex portion)-   144A, 144B, 244A, 244B: top surface of branched convex portion-   145, 245: concave portion-   146, 246: part of first substrate positioned between pixels-   147: convex structure-   147A: black matrix-   160: second electrode-   161: orientation regulating portion-   162: slit portion-   163: protruding portion (rib)-   248, 448: slit portion-   249, 449: protruding portion (rib)

The invention claimed is:
 1. A liquid crystal display device comprising:a first substrate; a second substrate; a first electrode provided on afirst surface of the first substrate, the first surface facing thesecond substrate, the first electrode including a plurality of convexand concave portions; a second electrode provided on a second surface ofthe second substrate; and a liquid crystal layer provided between thefirst substrate and the second substrate, wherein at least one of theconvex portions includes a plurality of stepped portions, wherein thestepped portions are provided at the convex stem portions, each of theplurality of stepped portions including a first surface at a centerportion of one of the convex stem portions, a second surface on thefirst surface, and a third surface outside the second surface, andwherein the first surface is higher than the second surface, and thesecond surface is higher than of the third surface.
 2. The liquidcrystal display device according to claim 1, wherein the convex andconcave portions includes a plurality of branched convex portions thatextend from the convex stem portions toward a pixel circumferentialportion.
 3. The liquid crystal display device according to claim 1,wherein the plurality of stepped portions are provided at the branchedconvex portions, each of the plurality of stepped portions comprising afirst surface extending from one of the convex stem portions and asecond surface positioned on both sides of the first surface, andwherein a height of the first surface is greater than a height of thesecond surface.
 4. The liquid crystal display device according to claim3, wherein each of the plurality of stepped portions declines from aside of one of the convex stem portions toward an end portion of one ofthe branched convex portions.
 5. The liquid crystal display deviceaccording to claim 1, wherein the convex and concave portions include aconvex stem portion formed in a frame shape at a pixel circumferentialportion and a plurality of branched convex portions that extend from theconvex stem portion toward the inside of a pixel.
 6. The liquid crystaldisplay device according to claim 5, wherein the convex stem portionincludes a first surface at an outer edge of the convex stem portion, athird surface at an inner edge of the convex stem portion, and a secondsurface located between the first and third surfaces, and wherein thefirst surface is higher than the second surface, and the second surfaceis higher than the third surface.
 7. The liquid crystal display deviceaccording to claim 5, wherein each of the branched convex portionsincludes a first surface that extends from a surface of the convex stemportion, and a second surface on both sides of the first surface, andwherein the first surface is higher than the second surface.
 8. Theliquid crystal display device according to claim 1, further comprisingan oriented film provided on the first surface of the first substrate.9. A liquid crystal display device comprising: a first substrate; asecond substrate; a first electrode provided on a first surface of thefirst substrate, the first surface facing the second substrate, thefirst electrode including a plurality of convex and concave portions; asecond electrode provided on a second surface of the second substrate;and a liquid crystal layer provided between the first substrate and thesecond substrate, wherein a convex structure is provided from a part ofthe first substrate positioned between pixels to a part of the firstsubstrate corresponding to a pixel circumferential portion, wherein acircumferential portion of the concave and convex portions is providedon the convex structure, wherein the convex structure includes a blackmatrix on a color filter layer; and wherein the convex and concaveportions include convex stem portions, and wherein a plurality ofstepped portions are provided at the convex stem portions, and whereineach of the stepped portions including a first surface at a centerportion of one of the convex stem portions and a second surface on thefirst surface, and wherein the first surface is higher than the secondsurface.